WO2025158023A1

WO2025158023A1 - Systems and methods for additively manufacturing an object using submerged arc welding and related devices

Info

Publication number: WO2025158023A1
Application number: PCT/EP2025/051843
Authority: WO
Inventors: Lars-Erik STRIDH; Markus LARSSON
Original assignee: Saam AB
Current assignee: Saam AB
Priority date: 2024-01-26
Filing date: 2025-01-24
Publication date: 2025-07-31
Anticipated expiration: 2026-07-26
Also published as: SE547409C2; SE2450081A1

Abstract

A method for additively manufacturing an object (200) using submerged arc welding is disclosed. The system (100) comprises a welding head (122) for providing layers of material to additively manufacture the object (200) at a substrate (21), and a frame assembly (500) for holding flux at the welding head (122), wherein the frame assembly (500), comprising at least one frame (501), is positioned on a support (130) and/or on a substrate (21) at which the object (200) is to be manufactured, wherein the substrate (21) is positioned on the support (130), wherein the system (100) is arranged to move the welding head (122) and the support (130) relatively each other in at least two dimensions. The method comprises operating (C130) the welding head (122) to form a respective layer (221-225) of the object (200) based on a shape of the object (200) to be manufactured, wherein the object (200) is formed by a plurality of layers (221-225) that comprises the respective layer (221-225), and wherein the method comprises, for at least some of the plurality of layers (221-225) of the object (200): providing (C140) at least one further frame (502) at said at least one frame (501), whereby the frame assembly (500) comprises said at least one further frame (502).

Description

SYSTEMS AND METHODS FOR ADDITIVELY MANUFACTURING AN OBJECT USING SUBMERGED ARC WELDING AND RELATED DEVICES

TECHNICAL FIELD

The embodiments herein relate to additive manufacturing, e.g. using Submerged Arc Welding (SAW), for creating, such as building, generating, or the like, objects made of metal. In particular, it is herein disclosed methods for additive manufacturing of a metal object using SAW and related devices, such as an object template panel, a flux holding device, for enabling additive manufacturing using SAW.

BACKGROUND

There exist various technologies for additive manufacturing, or 3D printing, of metal layers forming an object. For additive manufacturing of objects made of metal materials, a few weld-based technologies are presented in the following. Weld-based 3D printing, or metal additive manufacturing, using welding processes, involves the layer-wise addition of material through controlled welding techniques.

Directed Energy Deposition (DED) is a popular weld-based 3D printing technology that uses a focused energy source, such as a laser or electron beam, to melt and fuse metal powder or wire feedstock.

Wire Arc Additive Manufacturing (WAAM) utilizes an electric arc as the heat source to melt a continuous wire feedstock, which is then deposited layer by layer to build up the 3D object.

Electron Beam Additive Manufacturing (EBAM) employs a high-power electron beam to melt and fuse metal powder or wire feedstock, enabling precise control over the energy input and resulting in a high-quality build.

Laser Metal Deposition (LMD) utilizes a laser as the heat source to melt metal powder, which is typically blown into the melt pool, or to melt a wire. The process allows for localized heating and precise control over the deposition.

Plasma Arc Additive Manufacturing (PAAM) utilizes a plasma arc as the heat source to melt and fuse metal powder or wire feedstock. The high temperatures achieved with plasma enable the processing of a wide range of materials.

Ultrasonic Additive Manufacturing (UAM) combines ultrasonic welding and CNC machining to bond thin metal foils layer by layer. The process is solid-state, meaning there is no melting of the metal during the build. Submerged Arc welding Additive Manufacturing (SAAM) utilizes a Submerged Arc Welding unit to add metal layers, such as strings, beads, or the like, onto a substrate to successively form an object.

W02016070780A1 discloses a submerged arc additive manufacturing method for a metal structure. The submerged arc welding method for forming the metal structure is performed by that two electrodes of a welding power source respectively are connected to a welding torch and to a substrate. A granular flux and a metal welding wire are simultaneously conveyed onto a surface of the substrate. Power is turned on and an electric arc is produced between the substrate and the welding wire covered by the flux. Thus, allowing the welding wire and the surface of the substrate to be partly molten to form a weld pool on the surface of the substrate. Feeding of the welding wire and bringing forth of the flux is continued, and relative movement paths of the welding head and of the substrate are controlled. In this manner, the metal structure is formed layer-by-layer.

A problem related to additive manufacturing using SAW is that known technologies are restricted in terms of which shapes the object to be manufactured can have. Furthermore, the method used for additively manufacturing objects, with simple or complex shapes, can be cumbersome. Also, considerable post-processing is sometimes required, which extends manufacturing time. Postprocessing can include processing to smoothen surfaces of the object and the like. As a result, cost is increased as well.

SUMMARY

According to an aspect, there is provided a method, performed by a system, for additively manufacturing an object using submerged arc welding. The system comprises a welding head for providing consecutive layers of material to additively manufacture the object at a substrate, and an object template panel having a slot, whose shape corresponds to at least a portion of a main extension plane of at least one layer of the object, e.g. a transverse cross-section of the object at said at least one layer. The object template panel can be realized according to any embodiment thereof as disclosed herein. The substrate is positioned on a support. The system is arranged to move the welding head and the support relatively each other in at least two dimensions, preferably along z- axis and along x- or y-axis, more preferably three dimensions. The method comprises performing, by the system, the submerged arc welding to provide a respective layer of the object by means of the welding head, while moving the welding head and the object template panel relatively each other, e.g. in the horizontal plane, as constrained by the slot. The object template panel, e.g. a lower surface thereof, is located to match, at least in height, a preceding layer of the object, e.g. a top surface thereof. The preceding layer is preceding to the respective layer, whereby at least some flux is prevented from escaping through the slot, and vertically adjusting a distance between the object template panel and the support, e.g. by relative movement of the support and the object template panel, based on a layer thickness of the respective layer of the object, thereby locating the object template panel, e.g. the lower surface thereof, to match, at least in height, the respective layer, e.g. the top surface thereof, whereby at least some flux is prevented from escaping through the slot.

In this manner, the object template panel with the slot assists with ensuring that a blanket is formed over the arc during SAAM. Advantageously, for example a vertical wall, or slightly tilted wall can be efficiently manufactured.

In some embodiments, the vertically adjusting of the distance comprises lowering the support.

In some embodiments, the vertically adjusting of distance comprises raising the object template panel.

In some embodiments, the object has a shape of a wall, such as a vertical wall. The wall has at least one cross-section that is defined by, or at least partially defined by, the slot.

In some embodiments, the method comprises repeatedly performing the providing of the respective layer and the vertically adjusting of the distance, e.g. for a plurality of layers of the object to be manufactured.

In some embodiments, at least some layers of the plurality of layer have the same shape of their cross-sections as given by the slot.

In some embodiments, the providing of the respective layer of the object comprises moving the object template panel and the welding head relatively each other as constrained by the slot,), while maintaining the object template panel in a vertically fixed relation to the support.

In some embodiments, the providing of the respective layer comprises providing the respective layer horizontally.

In some embodiments, the vertically adjusting of the a distance between the object template panel and said each respective layer comprises arranging, such as moving or the like, the object template panel relatively said each respective layer to prevent flux from escaping downwards along the object wherein the distance matches the layer thickness, preferably by that the object template panel comprises a skirt which at least partially covers any existing gap between the respective layer and the slot to prevent escaping of flux.

According to another aspect, there is provided an object template panel for holding flux at an arc, which is generated during submerged arc welding performed to additively manufacture an object. The object template panel has a slot whose shape corresponds to at least one transverse crosssection of the object being additively manufactured layer by layer in a build direction, e.g. being vertical.

In some embodiments, the object template panel has a lower surface provided with a skirt extending along at least a portion of the slot, thereby preventing at least some flux from escaping downwards along the object during additive manufacturing using submerged arc welding. The skirt can extend along the long sides of the slot and optionally also along the short sides of the slot.

In some embodiments, the skirt comprises, such as is made of, manufactured of or the like, a textile material.

The object template panel is flexible, e.g. elastically flexible. A distal portion of the skirt is biased towards a central plane of the slot, thereby e.g. being arrangeable to abut a preceding layer of the object during welding. The central plane, or central surface, can run along a path describing the slot and the central surface can be perpendicular to the main extension plane of the object template panel.

In some embodiments, the object has a shape of a wall, such as a vertical wall. The wall has at least one cross-section that is defined by the slot.

According to a further aspect, there is provided a system arranged to additively manufacture an object using submerged arc welding. The system comprises a welding head arranged to provide consecutive layers of material to additively manufacture the object at a substrate. The substrate placeable on a support, and an object template panel as disclosed by any one of the examples herein, wherein the system is arranged to move the welding head and the support relatively each other in at least two dimensions, preferably along z-axis and along x- or y-axis, preferably three dimensions.

According to a still other aspect, there is provided a method, performed by a system, for additively manufacturing an object using submerged arc welding. The system comprises a welding head for providing layers of material to additively manufacture the object at a substrate, a flux holding device for holding/gathering flux at the welding head, a support plate provided with a plurality of ceramic panels arranged adjacent to each other and arranged to form an outward surface formed according to at least a portion of a shape, e.g. in at least the z-y plane, of the object to be manufactured. The outward surface faces away from the support plate and towards the object being manufactured. The support plate is arranged at the support. The substrate is positioned on a support. The system is arranged to move the welding head and the support relatively each other in at least two dimensions, preferably three dimensions. The method comprises providing a respective layer of the object using the welding head by conveying, e.g. in a horizontal plane, the welding head and the flux holding device along the support plate to apply the respective layer, and adjusting a distance between a welding head and the support based on a layer thickness of the respective layer of the object.

In this manner, the support plate with the ceramic panels assists with ensuring that a blanket is formed over the arc during SAAM. Advantageously, for example a complexly shaped object can be efficiently manufactured. In addition, geometry provided by the ceramic plates can be improved by the slag, e.g. between the ceramic plate and the object, and/or by the consumption of the ceramic plate during welding. In this manner, e.g. edges or unevenness between ceramic plates can be smoothened and/or evened out.

In some embodiments, the conveying of the welding head comprises conveying the welding head based on a shape, i.e. a shape of a horizontal cross-section, of the object to be manufactured.

In some embodiments, the flux holding device is defined in any one of the examples herein.

In some embodiments, the support plate is comprised in an object support assembly according to any one of the examples herein.

An object support assembly, comprising a support plate for supporting a set of ceramic tiles. The set of ceramic tiles when positioned at the support plate corresponds to a shape of a surface of an object to be additively manufactured using a system operated with a flux holding device according to any one of the examples herein.

In some embodiments, the support plate is made of metal, and the like.

In some embodiments, the object support assembly comprises a support structure arranged to support the support plate and to hold the support plate in a fixed relation to a substrate on which the object is formed.

In some embodiments, the object support assembly is connected, such as fixedly connected, to the support plate and to a support on which the object to be formed is placeable.

According to a yet other aspect, there is provided a flux holding device for holding flux at a welding head of a SAAM system, wherein the flux holding device comprises a frame arranged to hold flux receivable from a flux supply of the SAAM system, wherein the flux holding device is adapted to be mounted to the welding head, whereby the frame allows flux to be gathered to form a blanket over an arc generated during welding of a weld string as the SAAM system is operated. The frame has a base, arranged to face a currently deposited weld string during welding. The flux holding device is characterized by that the frame comprises a wall portion, such as a hatch, that is movable between a first position, in which the wall portion is arranged to protrude from the base and towards any existing preceding weld string, and a second position, in which the wall portion is arranged to allow the base to be located in close proximity to, or abut, any existing preceding weld string.

In some embodiments, the frame comprises a further wall portion arranged at the frame oppositely to the wall portion.

In some embodiments, the frame is provided with a protruding element at a lower, front edge of the frame. The protruding element is flexible by being able to adapt its shape to said any existing preceding weld string.

In some embodiments, the flux holding device is configured, by means of the wall portion and optionally the protruding element, to enable the SAAM system to additively manufacture an object built up by non-straight, vertically stacked weld strings. In some embodiments, the system is arranged to move the welding head and the support relatively each other in at least two dimensions, preferably along z-axis and along x- or y-axis, preferably three dimensions.

According to a still further aspect, there is provided a method, performed by a system, for additively manufacturing an object using submerged arc welding. The system comprises a welding head for providing layers of material to additively manufacture the object at a substrate, and a frame assembly for holding flux at the welding head. The frame assembly, comprising at least one frame, is positioned on a support and/or on a substrate at which the object is to be manufactured. The substrate is positioned on the support. The system is arranged to move the welding head and the support relatively each other in at least two dimensions, preferably along z-axis and along x- or y- axis, more preferably in three dimensions. The method comprises operating the welding head to form a respective layer of the object based on a shape of the object to be manufactured. The object is formed by a plurality of layers that comprises the respective layer, and wherein the method comprises, for at least some of the plurality of layers of the object, providing at least one further frame at, such as on top of, said at least one frame, whereby the frame assembly comprises said at least one further frame.

In this manner, the frame assembly assists with ensuring that a blanket is formed over the arc during SAAM. Advantageously, for example an object with overhang, such as a portion of a bridge or the like, can be efficiently manufactured.

In some embodiments, the providing of said at least one further frame comprises controlling an assisting moving mechanism to place said at least one further frame for inclusion into the frame assembly, whereby flux, e.g. provided into the frame assembly, is allowed to form a blanket over the weld pool.

In some embodiments, the method comprises obtaining information representing the shape of the object. Preferably the information includes layer information derived from a digital model of the object.

In some embodiments, the providing of the further frame comprises assembling, e.g. by means of the assisting moving mechanism, the further frame from at least two parts configured to form the further frame.

In some embodiments, the operating comprise moving, e.g. in the horizontal plane, the welding head and support relatively each other based on the shape of the object to be manufactured, and providing flux into the frame assembly.

In some embodiments, the providing of flux comprises providing an amount of flux that covers the respective layer.

In some embodiments, the operating of the welding head is performed for each layer of the object.

In some embodiments, the method comprises providing the frame assembly at the support and/or the substrate. The frame assembly encloses, e.g. in the horizontal plane, at least a region of the substrate where the object is to be formed.

In some embodiments, a set of actions comprises the operating of the welding head and the providing of the further frame. The method comprises repeating the set of actions.

In some embodiments, the repeating of the set of actions comprises repeating the set of actions by performing the operating of the welding head and then performing the providing of the further frame.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, at least some embodiments will be described in detail, with reference to exemplifying embodiments and to the enclosed drawings.

Figure 1 is a schematic overview of an example of a SAW unit.

Figure 2 is a schematic detailed view of a welding head of a SAW unit.

Figure 3 is a perspective view of an example of a system for additive manufacturing using SAW.

Figure 4 is a perspective view of another example of a system for additive manufacturing using SAW.

Figure 5 is top view of an example of an object template panel.

Figure 6 is a partial sideview of a further example of a system configured for additive manufacturing using SAW, wherein the system employs an object template panel.

Figure 7 through Figure 10 are side view of illustrative examples of the object template panel.

Figure 11a, Figure lib and Figure 11c are further views of examples of the system. Figure 12 is a side view of an object support assembly used in some examples.

Figure 13 is a perspective view of an example of the support plate comprised in examples of the object support assembly.

Figure 14, Figure 15 and Figure 16a through Figure 16d are views illustrating examples of the flux holding device.

Figure 17a and Figure 17b are side views illustrating additive manufacturing using the flux holding device and the object support assembly.

Figure 18a, Figure 18b and Figure 18c are flowcharts illustrating examples of the methods herein.

Figure 19 and Figure 20 illustrate examples of objects to be manufactured.

Figure 21 is a perspective view of a portion of a system configured to manufacture complex objects using SAAM.

Figure 22 and Figure 23 are views illustrating examples and details relating to the frame assembly.

DETAILED DESCRIPTION

As used herein, "flux", "granular flux", "welding powder" or "welding flux" refers to a type of granular insulative material that is made up of numerous small particles. In SAW, a purpose of the flux is to provide a blanket, e.g. over the welding region, which protects against sparks and spatter. The particles can have various shapes and sizes. The particles can have the same and/or different shapes. The shapes can be irregular and/or regular. The particles can have the same and/or different sizes. Various types of flux are available on the market, such as fluxes based on calcium fluoride, silica, manganese oxide, ferroalloys, aluminum, aluminum alloys, and more. The type of flux can be classified by applications, manufacturing process, chemical composition, metallurgy properties, basicity, granule structure, etc. During SAW, some of the flux melts, and then solidifies, thereby creating a slag cover at, such as around, under, over, and/or the like, an arc generated during welding.

As used herein, "welding region" or "welding process region" refers to a three-dimensional region in which welding occurs, or in which welding is planned to occur. The three-dimensional region can comprise one or more of an arc, a weld pool, a portion of the flux forming a blanket over the arc and/or portions thereof. As used herein, "template" or "object template panel" refers to a sheet-like member, such as a panel, provided with a groove, a slot or the like. The slot runs through the panel, e.g. from upper surface to lower surface, e.g. in case the panel is positioned horizontally, i.e. a main extension plane of the panel is horizontal. A vertical wall to be additively manufactured has a cross-section, e.g. parallel to the applied layers of material, typically perpendicular to a direction in which layers are stacked. According to at least some embodiments herein, the cross-section is horizonal when the object 200 is manufactured at the substrate. The cross-section can have two opposite sides. A path of the slot conforms to at least one the opposite sides of the wall, or both in examples where the sides are parallel. This means that, in some examples, a thickness of the wall can vary. Notably, the sides need not be straight lines. The path and/or the cross-section's side or sides can have any complex shape, e.g. curved lines, waves, irregular curves, polygon, sequence of straight lines with different directions, or combinations thereof and the like.

As used herein, "layer", "string", "bead", "metal layer", "metal string", "metal bead", "layer of material", "deposited material", "string of material", "metal bead", "weld string", "weld bead" or the like, refers to the metal material added onto a substrate or a preceding layer, where an object eventually is formed by a plurality of layers that have been added according to various embodiments herein using SAAM. The object may need to be processed to some extent after the SAW process in order to assume a desired shape and/or finish.

As used herein, "moving mechanism" refers to e.g. a robotic arm, a gantry, a linear actuator, a pneumatic actuator, an elevatable table, a lifting table, a position manipulator, a travel carriage, a turntable, a tractor unit for movement along a trace, or the like.

As used herein, "relative movement" can refer to that e.g. a first object and a second object are movable relatively each other. Thus, a relative movement can be achieved by that either or both objects exhibit changes in e.g. position, orientation and/or the like. As a consequence, the expression "the first object and the second object are moved relatively each other" implies that at least one of the first and second objects is moved, but does not exclude the possibility that both the first and second object are moved.

The term 'moves relatively' in the present invention refers to the dynamic relationship between object A and object B, wherein either or both objects exhibit changes in position, velocity, or orientation concerning each other. The relative movement encompasses translations, rotations, or any combination thereof, indicating a dynamic interaction between the said objects."

As used herein, "first axis", "longitudinal axis", "weld direction" or the like, refers to an x-axis, "second axis", "lateral axis", "transverse axis" or the like, refers to a y-axis and "third axis, "vertical axis", "build axis", "build direction" or the like, refers to a z-axis of an exemplifying cartesian coordinate system. Furthermore, as used herein "along the x-axis" and so on for the other axes, refers to movement in a positive x-direction of the x-axis and/or against said positive direction of the x-axis. It may here be noted that e.g. layer thickness, or layer height, is measured along the z-axis, while e.g. thickness or width of a wall, as an example of an object, is measured along the y-axis, or in the radial direction in case of a tube's wall thickness. A transverse plane can be defined as a plane that is perpendicular to the build axis. This means that at least one layer, i.e. the layer's main extension plane, of the object is parallel with the transverse plane. The main extension plane of the layer can be a plane in which the welding head is movable to deposit the layer. An example of the transverse plane can be a horizontal plane, e.g. defined by the x-axis and y-axis. A vertical plane can be defined by the z-axis and x-axis, i.e. a vertical longitudinal plane, or by the z-axis and the y-axis, i.e. a vertical transversal/lateral plane. In some examples, the coordinate system may be fixed to a movable welding head, which thus can move in the direction of the x-axis, whose direction can change as the welding head moves.

As used herein, "movement along one or more dimensions" refers to position along and/or rotation about one or more axis of a cartesian coordinate system. There can be one, two or three axes representing e.g. length, depth, and height. In some examples, radial coordinates, or other coordinate systems, can be used. For example, a moving direction of e.g. a welding head can be along the x-axis.

As used herein, "escape", "escaping", "leak", "leakage", and the like, refers to that e.g. flux, held by a device, such as the object template panel, the flux holding device, or the like, leaves the device and thus degenerates a formation of a blanket and/or requires additional filling of flux to ensure blanket formation. E.g. the flux leaves the device and falls downwards, e.g. along the object being manufactured, e.g. in a gap between the object and the device.

As a general comment for the concept of Submerged Arc Additive Manufacturing (SAAM), attention is brought to the fact that this process from a health and/or safety point of view is beneficial compared to gas metal arc welding. With SAW, the arc is submerged under the flux, no need to protect the human eye from radiation, or the skin from radiation. The radiation originating from the arc is thus at least partially blocked, or obscured, by the flux. There are no or very small amounts of welding fumes, since fumes are absorbed by the molten slag also submerged by the flux. Hence, there is no or little need to protect the operators from respiratory hazards/risks. The slag comprises remains from the wire and/or the flux. The slag is normally easy to remove from the manufactured object according to known manners, such as with metal brushes or the like. In some cases, when e.g. a rotational symmetrical object, rotated in the horizontal plane, is created, the slag can fall off by itself. Then, no particular measures need to be taken to remove the slag.

Figure 1 shows an example of a submerged arc welding system 10 to schematically illustrate some main components of such system. Submerged Arc Welding (SAW) is a joining process that involves the formation of an electric arc between a continuously fed wire, or electrode wire, and a substrate, such as a workpiece or the like, to be welded. A blanket of powdered flux surrounds and covers the arc. When the flux is molten, it protects the weld pool from oxygen, nitrogen, i.e. air in the atmosphere.

The system 10 comprises a flux supply 12, a tube 14, a wire reel 16, a wire feeder 18, a control unit 140, a power source 20, a welding head 122.

The flux supply 12, such as flux hopper or the like, can any type of container for holding flux 13. The tube 14, or hose, is connected to the flux supply 12 in order to be able to convey flux 13, e.g. by gravity or other, from the flux supply 12 to the welding head 122.

At the welding head 122, a flux exhaust 15, or orifice, of the tube 14 allows the flux to be expelled as a blanket over a welding region. The flow of flux, expelled through the flux exhaust 15, can be controlled by the control unit 140. In this manner, the flow of flux can be opened or closed.

Sometimes, control of the flow of flux may be dispensed with, since the flow of flux ceases when the flux is gathered at the flux exhaust 15 of the tube 15, where gathering at the flux exhaust occurs due to the physical properties of the flux, e.g. its low viscosity. This means that the flux at the exhaust 15 stops the flow of flux out from the tube 15.

The wire reel 16 of the system 10 is provided with a wire 30 that is feed to the welding head 122.

The control unit 140 is electrically connected to the power source 20, the welding head 122 and the wire feeder 18, e.g. for control thereof and/or for powering thereof.

The power source 20 is further connected to the substrate. The connection can be a direct connection or a connection via one or more other parts, components or the like. For example, the power source 20 can be connected to the substrate 21 via a support, shown in e.g. Figure 3 and Figure 4.

The welding head 122 can thus provide layers of material, e.g. from the wire 30, to build an object during welding and also provide flux for submerging an arc of during welding. In Figure 1, two pieces of a substrate 21, 22 are positioned on a support (not shown). The two pieces of the substrate can be arranged to become welded together by use of the SAW system 10. In general, a substrate 21, 22 can be positioned on the support by an operator, a user or the like, or by a moving mechanism, such as a robotic arm or the like. This means that the substrate can be positioned on the support manually or as controlled by a computer operating the moving mechanism. When the welding process begins by covering the substrate with flux and activating the welding head, the welding head can be moved along the gap between the two substrate pieces, which then are joined by a welding seam. The arc creates a weld pool at the substrate. A welding region can comprise the arc, the weld pool and parts of the substrates that are melted by the arc, which will blend into the weld pool. When the welding seam is created, material is added to the substrate. The added material can include metals, alloys, metal alloys, and the like.

Figure 2 is a magnified view of the welding head 122 that is directed towards the substrate 21, 22, i.e. the two pieces of substrate that can be welded together in this example. The wire 30 can be fed through a contact tube 24, such as a tip, a jaw or the like, of the welding head 122. The welding head 122 feeds the flux and the wire to the weld pool and/or a location of interest, such as a joint, a location where material is to be added for additive manufacturing.

When the system 10 is arranged to move the welding head 122 and the substrate 21, 22 relatively each other in three dimensions, at least some embodiments herein may be implemented in the system 10. Examples of how to achieve relative movement in three dimensions are provided in Figure 3 and Figure 4 below. This means that, in order to perform SAAM, the systems herein are configured for additive manufacturing using submerged arc welding. These systems can be referred to as SAAM systems.

Accordingly, the embodiments herein may be implemented in the exemplifying systems 100 according to e.g. Figure 3 and Figure 4. As shown, the system 100 comprises a support 130 on which the substrate 21 can be placed, such as put, mounted, located, or the like. Accordingly, the system 100 can be arranged to move the welding head 122 and the support 130 relatively each other in three dimensions. Expressed differently, the system 100 can be arranged to move the welding head 122 and/or the support 130 to move the welding head 122 and the support 130 relatively each other, e.g. in three dimensions This can be achieved by that the system comprises a system moving mechanism, such as one or more robotic arms, or the like. Here, the term "system moving mechanism" is used to distinguish the system moving mechanism from other moving mechanisms mentioned herein. The object to be manufactured can include at least a portion of the substrate 21. In some examples, however, the substrate 21 can be, more or less completely, machined off after the additive manufacturing using SAW is finished. Each of the systems 100, shown Figure 3 and Figure 4, can comprise a SAW unit 10, a support 130, and a control unit 140. The substrate 21 may preferably be made of the same type of material as the object 200 to be manufactured. This means for example that the substrate and the weld wire can be made of the same type of material, i.e. same chemical composition and the like. This allows the substrate to become a part of the object to be manufactured.

Generally, according to some embodiments herein, the support 130 can be a substrate platform, a portion of a floor at which the system 100 is standing, a table, a support block, a device for holding/gripping the substrate, a gripping member, a substrate grip, or the like. In some examples, the system 100 can comprise the support 130, such as a substrate platform, or the like.

Optionally, the SAAM system 100 comprises a flux collecting device (not shown), which can collect, e.g. by suction or the like, any remaining flux left at the object. A known flux collecting device can be a vacuum cleaner, e.g. arranged and configured for collecting flux.

In the example of Figure 3, the welding head 122 is arranged to be movable along three dimensions, while the support 130 is stationary. The welding head 122 is provided, such as mounted, fixed or the like, at a distal end of a robotic arm. In other examples, a gantry or the like may be used to achieve movement along one or more dimensions. In general, the welding head 122 can be mounted at any suitable moving mechanism, being capable of providing movement in one, two, or three dimensions.

Furthermore, in general, the welding head 122 can be arranged to be movable along one, two or three dimensions. This means that both the welding head 122 and the support 130 can be movable in three dimensions, but in many examples, it can be sufficient with fewer degrees of freedom for at least one of the welding head 122 and the support 130.

In Figure 4, the support 130 is arranged to be movable along three dimensions, while the welding head 122 is stationary. The support 130 is provided, such as mounted, fixed or the like, at a distal end of a robotic arm. In other examples, a gantry, wheeled lift table or the like may be used to achieve movement along one or more dimensions. The welding head 122, including an outlet for feeding of the wire, and an orifice 15 for exhaust of flux, can have a fixed position and/or a fixed orientation. Generally, the support 130 can be arranged to be movable along one, two or three dimensions. At the support 130, a substrate 21, which may or may not, or to some extent, become part of the object 200 to be manufactured. Layers of material can thus, during SAAM, be deposited to form the object 200. The layers can have the same shape or different shapes from each other in order to form the object.

As further examples, the welding head 122 can be movable in one dimension, while the support 130 is movable in the other two dimensions, the welding head 130 is movable in two dimensions, while the support is movable in the other dimension. E.g. the welding head is movable in e.g. height, but not in width/length, while support is movable in width/length but not in height etc..

This means that the system 100 is arranged to move the welding head 122 and/or the support 130 to move the welding head and the support relatively each other in at least two dimensions.

In order to perform additive manufacturing, the welding head 122 and the support 130 can preferably be moveable relatively each other in three dimensions, but sometimes it can be sufficient with two dimensions, such as when building a flat and straight, completely vertical wall. However, such completely vertical wall can have a varying width, thanks to adjustment of welding parameters. The welding parameters includes one or more of:

• Welding current measured in Amp. This is the parameter that determines the deposition rate (kg/h), it will determine how deep into the previous deposited bead the heat will penetrate thereby ensuring complete metallic fusion between the layers. The welding current is also selected in dependence of a speed of the feeding of the wire.

• Welding voltage (potential difference between negative and positive polarity) measured in Volts (V) and it will decide the length of the arc, thereby also will influence the width of the deposited bead.

• Welding speed (mm/s) the movement of the welding arc along the programmed path, e.g. according to the slot, e.g. a trace along the slot's length. The welding speed influences width of the deposited weld string, height of the deposited weld string and to some extent penetration into a substrate and/or a preceding layer of the object.

• Current, voltage and welding speed are jointly dimensioning the heat input to the substrate or the previously deposited layer (kJ/mm).

• a speed of the feeding of the wire, aka wire feeding speed, can be the speed, e.g. in mm/s, at which the wire feeder 18 feeds out wire 30 to the welding head 122, and also out from the welding head 122. • a contact tube distance from the contact tube to the substrate or the preceding layer. The distance, referred to as electrical stick-out in some related literature, can be 25-40 mm, or the like.

According to SAAM, any one of the systems described above can operate, based on a shape of an object to be manufactured, the welding head to form a respective layer of the object. The object is thus formed by a plurality of layers that comprises each of the layers, e.g. all or some of the layers added to the substrate. As an example, the system can operate the welding head by moving, e.g. in a horizontal plane and e.g. along the x-axis and/or along the y-axis, the welding head and support relatively each other based on the shape of the object and by expelling flux from the flux supply at the weld region. Before a subsequent layer is deposited, it can be beneficial to remove any existing slag. Also, before the subsequent layer is deposited, a vertical distance between the support and the welding head can be adjusted, e.g. based on a thickness of a layer just being completed, aka a current layer, and/or based on a thickness of the subsequent layer. Sometimes, the thicknesses, e.g. along the z-axis, of the current and subsequent layer are equal, but they can also be different from each other.

According to further examples, any one of the systems above can be provided with two wires, aka welding wires. SAW systems with two wires are known in the art.

In some applications, it is desired to build a wall, such as a vertical wall, using any one of the systems above when being adapted to additive manufacturing. In order to accomplish the manufacturing of a vertical wall at a substrate, an object template panel of at least a portion of a horizontal cross-section of the wall can be used. The object template panel ensures that flux can gather at a region where submerged arc welding is to take place.

An example of the object template panel 150 is shown in Figure 5.

In some examples, the object template panel 150 is configured and/or arranged to hold flux at an arc, generated during submerged arc welding performed to additively manufacture the object 200. The object template panel 150 has a slot whose shape corresponds to at least one transverse crosssection of the object 200 being additively manufactured layer by layer in a build direction, e.g. being vertical. The build direction can be perpendicular to a main extension plane of the object template panel 150.

In some examples, the object template panel 150 has a lower surface 153 provided with a skirt 158 extending along at least a portion of the slot 152, thereby preventing at least some flux from escaping downwards along the object 200 during additive manufacturing using submerged arc welding.

In some examples, the skirt 158 comprises, such as is made of, manufactured of or the like, a textile material, a heat resistant material, a textile heat resistant material, or the like.

The object template panel 150 can comprise a flat panel 151 that can have the slot 152, e.g. penetrating the flat panel 151 and extending through the flat panel 151, e.g. from an upper surface 155 to a lower surface 153 of the flat panel 151, sometimes referred to as the upper surface 155 and the lower surface 153 of the flat panel 151. The flat panel 151 can represent the main extension plane of the object template panel 150. In some examples, the object template panel 150 can be provided with walls (not shown), e.g. along the flat panel's 151 outer periphery, to gather and maintain flux at the upper surface.

The slot 152, or groove, can have the desired geometry of at least a portion of the object, such as the wall, the vertical wall or the like, to be manufactured. For examples, the slot can have a shape that corresponds to at least a portion of a horizontal cross-section of at least one layer of the wall, wherein the horizontal cross-section refers to the orientation of the cross-section during welding of the wall.

A width 154 of the slot 152 can be set to match a thickness of the wall. The slot 152 can be wider than the width of the weld string to be deposited. Typically, the width 154 of the slot 152 is 4 to 15 mm, preferably 8 to 10 mm, wider than the weld string, e.g. 2 to 5 mm on each side of the weld string. The gap between the object to be manufactured and the slot 152 can be covered by a skirt 158, see Figure 6, on the lower surface 153 of the object template panel 150.

The width of the slot 152 can, in some examples, be adjustable in order to manufacture walls of different widths, or thicknesses, e.g. measured along the y-axis. This can be achieved by that the flat panel 151 comprises two portions 151a, 151b. Each of two portion 151a, 151b can include a respective side of the slot 152. A screw (not shown), or the like, can be provided on one of the portions 151a and a threaded hole (not shown), or the like, can be provided on the other one of the two portions 151b such as to enable adjustment of the distance between the respective sides of the slots 152. In this manner, the width 154 of the slot 152 can be adjustable. The two portions 151a, 151b can sometimes be separable from each other. In some examples, the adjustment of the width can be realized by mounting one, or preferably two, linear actuators at the two portions 151a, 151b. Each actuator can then be arranged to adjust the width of the slot 152 between the two portions. When the object template panel 150 comprises, such as includes, or the like, the slot 152 with an adjustable width, it may be that the width is adjusted during manufacturing of the object, such as the wall, or the like. For example, adjustment of the width can be performed before beginning of deposition of the respective layer, or after finalizing the deposition of the respective layer. In the same or similar manner, it is contemplated that different object template panels can be used during the manufacture of one and the same object.

The flat panel 151 can have a thickness 156 at least 2 mm, 3 mm, 4 mm or the like. The thickness, e.g. along the z-axis, can further be less than 25 mm, 20 mm, 15 mm, or the like. Typically, the thickness can be in a range of e.g. 3 mm to 20 mm, 4 mm to 15 mm, 5 mm to 10 mm or the like. In some examples, the thickness of the flat panel 151, e.g. measured along the z-axis, corresponds to a height of the weld string to be deposited, aka a thickness of the deposited layer. In this manner, any slag remaining on a deposited layer will protrude over an upper surface of the flat panel 151. Consequently, the remaining slag can be removed, e.g. by means of a scraping tool, such as a scape, a metal brush, a plane tool, or the like. The slag can thus be removed before a new layer is deposited. Furthermore, an advantage can be that the amount of flux required to form a blanket over the arc during welding is kept low, i.e. thanks to that the slot forms a well that is filled with flux, which e.g. in case of a very thin flat panel would form an irregular pile, or heap, with unnecessarily large volume.

When additively manufacturing the wall, it may be beneficial to have a welding head that is movable in the XY-plane, e.g. only in the XY-plane. The support may then be movable in the Z-direction, e.g. only in the Z-direction.

The object template panel 150 can be made of steel, aluminum, bakelite, a temperature resistant plastic, or the like.

Figure 6 illustrates a portion of a system 100, such as any one of the aforementioned systems, when adapted for manufacturing a wall. In this example, the object template panel 150 is fixedly mounted and the support 130 is movable along the z-axis, or at least along the z-axis. In this example, a lifting table is used to move the support 130 along the z-axis, but in other examples a robotic arm, a linear actuator, or the like, can be used for movement along the z-axis. The support 130 may be said to include the lifting table. The support 130 can, also or alternatively, include a linear actuator, an elevatable platform or the like.

A height of the lifting table can be controlled by the control unit 140. This means that the control unit

140 can be configured to control the height of the support 130. An accuracy of the control of the height can for example be +/-0.5 mm, +/- 1 mm, +/- 1.5 mm or the like. To some extent, the accuracy of the control is dependent on a thickness (along z-axis) of the weld strings to be deposited. As an example, the accuracy of the control can be at the most one fourth of such a thickness or the like.

Thanks to the object template panel 150 the flux will be prevented from falling down on the substrate 21 and/or the support 130 when a plurality of layers of material has been provided, or welded, on top of each other. Accordingly, the object template panel 150 ensures that the flux protects the arc and the weld pool from e.g. ambient air. During welding according to SAAM, the object template panel 150 is located in relation to, e.g. at a particular distance from, a preceding layer. The particular distance depends on the layer thickness of a currently deposited layer. The thickness of the layer depends on e.g. a diameter of the wire, which e.g. can vary from 1.6 mm to 6 mm, and the welding parameters, such as current, voltage, welding speed and the like. A typical layer thickness is between 2 mm and 8 mm.

In the following, it is described how to weld an object, such as a wall or the like, while ensuring that the welding region is covered, e.g. sufficiently covered, with flux.

Referring to Figure 6 and Figure 18a, an exemplifying method, e.g. performed by the system 100 and/or the control unit 140, for additively manufacturing an object 200, using submerged arc welding, is disclosed. This means that the method can be computer-implemented. The object 200 can have a shape of a wall 250, such as a vertical wall. The wall 250 has at least one cross-section that is defined by, or at least partially defined by, the slot 152.

As mentioned, the system 100 comprises a welding head 122 for providing consecutive layers of material to additively manufacture the object 200 at a substrate 21, and an object template panel 150 having a slot 152, whose shape corresponds to at least a portion of a main extension plane MP of at least one layer 221-225 of the object 200, e.g. a transverse cross-section of the object 200 at said at least one layer 221-225. The main extension plane MP can be a plane in which the welding head 122 moves when depositing the layer, e.g. a horizontal plane. The substrate 21 is positioned on a support 130. The system 100 is arranged to move the welding head 122 and the support 130 relatively each other in at least two dimensions, preferably along z-axis and along x- or y-axis, more preferably three dimensions.

Initially, in the example of Figure 6, the table is set to a height that allows the table to be lowered a distance that is equal to or greater than a final height of the object 200 to be manufactured. The substrate 21 is placed on the support 130. Furthermore, the object template panel 150 is placed above the substrate 21, e.g. in close proximity of the substrate 21. As an example, the object template panel 150 is located 2 - 8 mm above the substrate, preferably 5 mm or the like. The object template panel 150 can be fixed in relation to movement of the lifting table. In other examples, as indicated above, it may be that the lifting table is fixed and the object template panel 150 and the welding head 122 are moved in relation to the lifting table.

One or more of the following actions may be performed.

Action A110

The system 100 performs the submerged arc welding to provide a respective layer 221-225 of the object 200 by means of the welding head 122, while moving the welding head 122 and the object template panel 150 relatively each other, e.g. in the horizontal plane, as constrained by the slot 152. The object template panel 150, e.g. a lower surface 153 thereof, is located to match, at least in height, a preceding layer 221-225 of the object 200, e.g. a top surface 260 thereof. The preceding layer 221-225 is preceding to the respective layer 221-225, whereby at least some flux is prevented from escaping through the slot 152. As an example, during provision of the respective layer 221-225, the object template panel 150 can be fixed in relation to the support 130.

Accordingly, the welding head 122, e.g. as controlled by the control unit 130, provides a respective layer 221-225 of the object 200 while the object template panel 150 is located to match, at least in height, a preceding layer 221-225 being preceding to the respective layer 221-225. In this manner, at least some flux is prevented from escaping through the slot 152 during submerged arc welding that is performed, by the system 100, for the provision of the respective layer 221-225.

As an example, a lower surface of the object template panel 150 can be located to correspond to a height of the preceding layer 221-225, i.e. the lower surface of the object template panel 150 is located at a (first) position that is at, or lower than, a (second) position along z-axis of the upper surface of the preceding layer 221-225, e.g. where the (second) position is in the vicinity of the slot, or at a lower edge of the slot.

The welding region will typically be in level with the object template panel 150, which gives the flux necessary support and thus ensures that the flux covers the welding region. As an example, an upper surface 155 of the object template panel 150 can be located above, e.g. 1-5 mm above, 2-3 mm above, a combination thereof, or the like, the respective layer 221-225 currently being deposited.

The respective layer 221-225 is applied while the welding head 122 is moved, e.g. in a horizonal plane, according to the shape of the slot 152. As an example, this can be achieved by that the control unit 140 is configured, such as programmed, to move, e.g. in X- and Y-directions, the welding head 122 in relation to the substrate 21 according to the shape or geometry of the slot 152. In other examples, the object template panel 150 and the support 130 can be moved in synchrony while the welding head 122 remains stationary, when the respective layer 221-225 is applied.

In some examples, at least some layers of the plurality of layer 221-225 have the same shape of their cross-sections as given by the slot 152.

In some examples, action A110 comprises moving the object template panel 150 and the welding head 122 relatively each other as constrained by the slot 152, e.g. according to a horizontal shape of the slot 152, while maintaining the object template panel 150 in a vertically fixed relation to the support 130.

In some examples, action A110 comprises providing the respective layer 221-225 horizontally.

It can here be noted that, in action A110, the system 100 may, as necessary, provide one or more strings of material, to achieve a desired thickness of the wall, i.e. without adjustment of the distance D, aka without adjustment of the relative distance between the support 130 and the object template panel 150 along the z-axis. For example, two weld strings can be deposited next to each other, e.g. in the xy-plane.

Action A120

The system 100 vertically adjusts a distance D between the object template panel 150 and the support 130, e.g. by relative movement of the support 130 and the object template panel 150, based on a layer thickness of the respective layer 221-225 of the object 200, thereby locating the object template panel 150, e.g. the lower surface 153 thereof, to match, at least in height, the respective layer 221-225, e.g. the top surface 260 thereof, whereby at least some flux is prevented from escaping through the slot 152. In some examples herein generally, the lower surface 153 is located, along the z-axis, at or lower than the top surface 260 of the preceding layer, i.e. the respective layer 221-225.

In some examples, the system 100 adjusts the distance D such that the object template panel 150 is at a position that corresponds to, or is lower than, the respective layer 221-225. E.g., the lower surface 153 corresponds to, or is lower than, the respective layer 221-225. Here, the respective layer can also be referred to as a preceding layer, since it was deposited in action A110 above.

Furthermore, in some examples, the system 100 can adjust, such as set, determine, or the like, the distance D such that the object template panel 150 is at a position that corresponds to, or is lower than, a thickness, or height, of a subsequent layer to be deposited after the respective layer 221-225. In general, the system 100 can adjust the distance D to ensure that the welding head 122 can create a blanket of flux that covers the arc during welding, while at the same time avoiding, or at least reducing, leakage of flux in a gap G between the slot 152 and the preceding layer.

In some examples, the vertically adjusting A120 of the distance comprises lowering the support 130. In some examples, the vertically adjusting A120 of distance D comprises raising the object template panel 150.

In some embodiments, a set of actions can comprise action A110 and action A120. Then, the system 100 can repeat the set of actions. As an example, the method comprises repeatedly performing the providing A110 of the respective layer and the vertically adjusting A120 of the distance D, e.g. for a plurality of layers 221-225 of the object 200 to be manufactured.

In some examples, the vertically adjusting A120 of the a distance D between the object template panel 150 and said each respective layer 221-225 comprises arranging, such as moving or the like, the object template panel 150 relatively said each respective layer 221-225 to prevent flux from escaping downwards along the object 200 wherein the distance D matches the layer thickness, preferably by that the object template panel 150 comprises a skirt 158 which at least partially covers any existing gap G between the respective layer 221-225 and the slot 152 to prevent escaping of flux.

In more detail, as an example, after the first layer is deposited, the lifting table can be lowered with the same amount as the height/thickness of the deposited layer. The thickness pf the deposited layer is dependent on the welding parameters determined for each wall application.

The combination of the parameters is determined by performing welding tests prior to the manufacturing of the wall and/or can be dynamically altered during the process, such as between the application of consecutive material layers.

This is beneficial in order to improve precision of the wall, e.g. in terms of width, height and smoothness of the sides of the wall. Smoothness, or resolution, refers to that the fusion between each layer at the side of the wall is as even, or smooth, as desired, in order to reduce the amount of machining needed after the wall is manufactured.

Turning to Figure 7 through Figure 10, a few exemplifying views of the object template panel 150 are shown. In these examples, the object template panel 150 can be provided with one or more skirts 158, such as a rims, flaps, frames or the like. For simplicity, said one or more skirts 158 is referred to as "skirt 158" in singular, but it is to be understood as "one or more skirts 158" when applicable. In this manner, any existing gap between the slot 152, i.e. inner edges of the slot 152, and a previously deposit layer of material, i.e. to build-up the object, is, at least partially, covered, by the skirt 158, to prevent at least some flux from falling down along the sides of the wall 200.

The skirt 158 can be made of a woven or non-woven textile material, a heat resistant material, a textile and heat resistant material, or the like.

The skirt 158 is provided at least partially along the slot 152, e.g. at an underside of the object template panel 150. The skirt 158 can be applied on the underside of the template, e.g. on one or two sides of the slot, or groove. The skirt 158 can slide against the wall 200, e.g. a latest applied layer of the wall, when the distance D is adjusted. As mentioned, the object template panel 150, optionally including the skirt 158, can prevent the flux from leaking down and away from the welding region.

In some examples, and as shown in figure 7 in a relaxed state of the skirt 158, the skirt 158 comprises one or more flaps that are biased towards a first position, in which the flaps are titled towards a central plane following along the slot 152, the central plane being perpendicular to a main extension plane of the object template panel 150, and form an angle of 90 degrees or less with respect to the main extension plane of the object template panel 150, the skirt 158 of one side of the slot 152 at least partly extending towards an opposite side of the slot 152 when in the relaxed state, i.e. the first position.

Expressed differently, in some examples, the skirt 158 is flexible, e.g. elastically flexible. A distal portion 159 of the skirt 158 is biased towards a central plane 157 of the slot 152, thereby e.g. being arrangeable to abut a preceding layer of the object 200 during welding. The distal portion 159 is distal relatively the slot, e.g. the distal portion 159 is distal to the skirt's connection to the lower surface 153 of the object template panel 150. As understood from Figure 5 and Figure 7, the central plane 157 can be a curved surface that is perpendicular to the xy-plane. The central plane 157 can be located at the middle of the slot, i.e. centrally.

In this manner, the object to be manufactured, such as a wall, can be allowed to have some tilt by adjusting both vertical and horizontal position, e.g. along the y-axis. Alternatively or additionally, the object to be manufactured can be allowed to have a varying width, e.g. along the y-axis, e.g. by varying the current and/or the welding speed. E.g. an increase of welding speed implies a reduction of the width and/or a reduction of the current implies a reduction of the width.

In the examples above, the object 200 to be manufactured has been exemplified by a wall, such as a vertical wall. The wall 250 has at least one cross-section that is defined by the slot 152.

In view of the above, there is provided, such as in Figure 3 or Figure 4, a system 100 arranged to additively manufacture an object 200 using submerged arc welding. The system 100 comprises a welding head 122 arranged to provide consecutive layers of material to additively manufacture the object 200 at a substrate 21. The substrate 21 placeable on a support 130, and an object template panel 150 as disclosed herein. Moreover, the system 100 is arranged to move the welding head 122 and the support 130 relatively each other in at least two dimensions, preferably along z-axis and along x- or y-axis, preferably three dimensions.

The same or similar method can be used to manufacture other types of objects, such as tubes, pipes, annular members, circular member or the like.

In these examples, the support 130 is rotatable, such as circularly rotatable. As an example, the lifting table can be a rotating table having height control adjustment.

Furthermore, to give support to the flux in this case the slot of the object template panel 150 can be, or can be replaced by, a circular through-hole. An inner diameter of the through-hole may preferably be matched to an outer diameter of the object 200, such as a tube or the like, to be manufactured. The inner diameter of the through-hole can be larger than, such as slightly larger than, the outer diameter of the object 200. In some examples, as described above, a skirt 158 can be provided along the inner diameter of the through-hole, or slot. In this manner, as above, any existing gap between a previously deposited layer and the object template panel 150 can be covered, or at least partially covered. The same or similar features of the skirt 158 as mentioned above can be applied also when manufacturing a tube.

In some cases, it may be necessary to prevent flux from falling into the center of the tube to be manufactured. However, for example when the inner diameter and/or a length of the tube is small or if large amounts of flux is available such as to fill the interior of the tube, the flux can sometimes gather in the interior of the tube and thus fill the interior of the tube. Then, the flux, or recently expelled flux, will be able to cover the welding region, since the recent flux cannot fall into the interior being filled with previously expelled flux.

With the examples that require a support for preventing, or partly preventing, flux to fall into the interior of the tube, an inner circular support 230 can be used. Similarly as above, an outer diameter of the inner circular support can be less than, such as slightly less than, an inner diameter of the tube to be manufactured.

The inner circular support 230 can be realized by one or more circular elements 231, 232, 233 such as plates, rings, circular frames, or the like.

As the tube grows higher and higher by the additive manufacturing using submerged arc welding, it can be desired to adjust, such as increase, or the like, the height of the inner circular support 230. This can be achieved by using a plurality of inner supports 230 having different heights. Hence, as an example, the system 100 can be configured to adjust a height of the inner circular support, e.g. by replacing one inner circular support 230 with another inner circular support having a higher height than said one inner circular support 230. The higher heights can be adapted to a thickness of the deposited layer of material. Alternatively or additionally, the system 100 can be configured to adjust the height of the inner circular support 230 by placing one or more circular elements 231, 232, 233 on top of each other and on the substrate 21 and/or the support 130. In this manner a stack of inner circular elements 231-233, forming the inner circular support 230, prevents the flux from falling into the interior of the object 200 being manufactured. Sometimes, it may be sufficient with an inner circular support 230 having a height that corresponds to, or is greater than, a length of the tube to be manufactured. Here, the length of the tube can be along the z-axis.

In some examples, the object template panel 130 may not be used at all. In such example, support for the flux is provided by a set of outer support rings and a set of inner support rings. The inner and outer diameters of the set of outer and inner support rings, respectively, can be chosen as explained above with respect to the outer and inner diameters of the tube to be manufactured. Furthermore, the system 100 can be configured to put, e.g. after the provision of a respective layer, another outer and inner support ring on the previous ones. The system 100 can be configured to control one or more further robotic arms in order to put the outer and inner support rings at the object 200.

The outer and/or inner support rings can in some cases be replaced by one or more flux holding devices as described below in relation to e.g. Figure 14.

An exemplifying method, performed by the system 100, for additive manufacturing of a tube using submerged arc welding can be achieved by applying minor modifications to action A110 and A120 above. The same or similar reference numeral as in the example of building a wall is used when applicable. Features relating to the general system and/or general additive manufacturing using SAW give above are also applicable in this example.

The substrate 21 is placed on the support 130. Furthermore, the object template panel 150 and/or one or more circular support frames are placed above, or on, the substrate 21, e.g. in close proximity of the substrate 21. E.g. an inner support can be placed at the center of the tube to be manufactured.

One or more of the following actions may be performed.

Action A110 - modified as compared to action A110 above The welding head 122, e.g. as controlled by the control unit 130, provides a respective layer 221-225 of the object 200 while the object template panel 150 is located to match, at least in height, a preceding layer 221-225 being preceding to the respective layer 221-225. The support 130 can be rotated during deposition of the respective layer. Thanks to the object template panel 150 and/or the inner circular support, at least some flux is prevented from escaping through the slot 152 during submerged arc welding performed, by the system 100, for the provision of the respective layer 221- 225.

The welding region will typically be in level with the object template panel 150, which gives the flux necessary support and thus ensures that the flux covers the welding region.

The respective layer 221-225 is applied while the support 130 is rotated, e.g. in a horizonal plane.

Action A120 - same or similar as above

The system 100 vertically adjusts a distance D between the object template panel 150 and the support 130 based on a layer thickness of the respective layer 221-225 of the object 200.

Again, several weld strings or layers of material can be deposited at the same height, but at different radial distances from the center of the tube in order to achieve a desired thickness of a wall of the tube. For the tube, it can be preferred to observe the system with reference to a polar coordinate system. Then, the thickness of the wall of the tube is measured along a radial axis and e.g. a moving direction can be along an angular axis.

In view of action A110 and A120, the build of the tube starts at a height of the support that allows lowering of the rotating support to the designed height of the tube to be produced. In the same way as described above for building walls, the welding parameters are set in order to produce the desired width and height of the weld strings to fit with the wall thickness of the object produced.

In view of the above, in one example the inner circular support can be replaced by any embodiment of the flux holding device described herein.

With the embodiments using the object template panel 150, it may be that the upper surface of the object template panel 150 preferably is positioned 1-4 mm, in more detail 2-3 mm, higher than an upper surface of the preceding layer. As another example, the upper surface of the object template panel 150 can be at a vertical distance from the preceding layer that matches, or is greater than, a thickness of the layer to be deposited. 1

Figure 11 show further examples of the system 100. The object template panel 150 can be movable along the Z-axis. The system 100 and/or the control unit 140, can thus be configured to move the object template panel 150, e.g. using a template moving mechanism, such as an elevatable grip, or the like, that is fastened to the object template panel 150. Here, the term "template moving mechanism" is used to distinguish this moving mechanism from other moving mechanism in mentioned in the present disclosure. The template moving mechanism can be realized by any suitable means of providing height movement of the object template panel 150.

In some embodiments, the object 200 to be additively manufactured using submerged arc welding can have other wall angles than the vertical one as in some examples above relating to the manufacturing of the vertical wall. With reference to the examples above, this can, to some extent, be achieved by that the support 130 is titled and then the wall can be built vertically with respect to a global horizontal plane, and as a result of the titling, the wall will be built at an angle relatively the substrate 21.

In the following example, the object can be a complexly shaped wall deviating from the appearance of a vertical wall. This solution takes advantage of ceramic backing, which is typically applied when two substrates are welded together and/or after such welding together. The ceramic backing can include the provision of one or more ceramic plates under a gap between two substrates that are to be welded together.

An advantage of ceramic backing is that it gives a rear side of a welding seam between two substrates a smooth and even surface. To this end, the ceramic backing can be configured with a properly shaped surface facing the two substrates. During welding, the weld pool melts a top surface of the ceramic backing plate(s) and it forms a glass-like slag which shapes the back side of the seam, or bead. Ceramic plates are poor heat conductors, and it therefore substantially maintains its form and shape during the process and prevents the weld pool from penetrating into the ceramic. However, the ceramic is consumed after welding and therefore the ceramic plates cannot be reused in their current state after use but need to be replaced before the next process iteration.

In order to manufacture an object, such as a wall, a non-vertical wall, a vertical wall, a complexly shaped wall or the like, a support plate or each support plate can be provided with a plurality of ceramic plates, such as ceramic backing plates, ceramic blocks, ceramic pieces, ceramic polygon blocks, ceramic rectangular blocks, ceramic rectangular blocks with beveled and/or chamfered sides, and/or beveled and/or chamfered edges, or the like. The support plate can be shaped, at least coarsely, according to a desired shape of at least one side of the object to be manufactured. When the plurality of ceramic plates is positioned on the support plate, the plurality of ceramic plates will then also, at least coarsely, conform to the shape of the side of the object.

The ceramic plates of the plurality of ceramic plates can have different or the same shape and/or size. For simplicity, the ceramic plates have the same shape and size in the associated Figures.

Figure 12 shows an example of an object support assembly 300, comprising a support plate 320 for supporting a set of ceramic tiles 341-344. The set of ceramic tiles 341-344 when positioned at the support plate 320 corresponds to a shape of a surface of an object to be additively manufactured using a system 100 operated with a flux holding device 400 according to any one of the examples herein. In some examples, the support plate 320 is made of metal.

The object support assembly 300 can comprise a base 310, and a support structure 330, such as a support leg, a support truss, or the like. The base 310 can be realized in the form of the support 130.

In some examples, the object support assembly 300 comprises a support structure 330 arranged to support the support plate 320 and to hold the support plate 320 in a fixed relation to a substrate 210 on which the object is formed.

In some examples, the object support assembly 300 is connected, such as fixedly connected, to the support plate 320 and to a support 130 on which the object to be formed is placeable.

A thickness of the support plate 320 can be in a range of 1-10 mm, 1-5 mm, 1-3 mm, or the like. A size, such as width and/or height, of the support plate 320 can be selected according to size and/or shape of object to be manufactured.

As mentioned, a plurality of ceramic plates 341-344 can be positioned on the support plate 320. Depending on the shape of the object to be manufactured, some or all of the plurality of ceramic plates 341-344 can be fastened to the support plate 320.

One or more ceramic plates 341-344 can thus be placed at the support plate 320. The support plate 320 can be made to fit, such as hold, the number of ceramic pieces 341-344, by that its side edges can be bent 90 degrees, thereby supporting the ceramic pieces like a tray. It may be preferred that said one or more ceramic plates 341-344 are fixed to the support plate 320, while any fastening means used does not obscure a surface, formed by the plurality of ceramic plates, towards the side of the object to be manufactured. Alternatively, the ceramic pieces 341-344 can merely rest on the support plate 320, for instance being stacked on top of each other without fastening so that the ceramic pieces 341-344 rest upon each other in the stack, and also on the support plate 320. Together, the ceramic pieces 341-344 can form a structure extending further in the z direction from the support 130 than what a single one of the ceramic pieces 341-344 would be able to.

Depending on the object to the manufactured and the particular application of the object support assembly 300, the support plate 320 may or may not be provided with reinforcing steel rods, e.g. in a direction from the base 310 towards a periphery of the support plate 320.

As an overview, in one example, the method of manufacturing an object 200 using the object support template 300 begins by starting to deposit material at the substrate, at a bottom row of the support plate 320. Next, weld string after weld string is deposited onto of the previous weld string until the desired object 200 is formed. As mentioned previously, should a thickness of the object require, the method can start over from the bottom row again and weld a further string next to and/or on top of the previous strings. When the object 200 is finalized, the support plate 320 can be removed and a back side of the object 200, i.e. the side facing the ceramic plates 341-344 can be cleaned from remaining slag, e.g. by means of steel brushing.

An advantage with the object support assembly 300 can be that even though the ceramic plates describe a rugged, angular and/or edgy shape, the final shape can become smoother than that rugged shape, since the ceramic plates are consumed to some extent during welding and the melted ceramic material evens out the edges/angles between the ceramic plates, i.e. the non-melted portions of the ceramic plates. Therefore, the method described can successfully form complex geometries such as fan blades or the like. In particular, both developable and doubly curved wall structures can be manufactured.

Figure 13 shows an example of detailed view of the support plate 320. The ceramic plates 341-344 are placed on the support plate 320. Next, the support plate 320 can be positioned, using the support structure 330, to allow an object to be built, e.g. layer by layer, according to the shape of the support plate 320. In this example, the support plate 320 is flat, but in other examples, the shape of the support plate 320 can be more complex, e.g. according to the shape of the object to be manufactured. Hence, each of the pieces 341-344 can be identical or different, in particular in terms of their thickness.

In general, flux holding devices are accessories used in the process of SAW for collecting, maintaining and gathering flux, e.g. to ensure that the flux forms a proactive blanket at the weld pool. They are most commonly used for multi electrode welding of longitudinally welded pipes. All conventional uses of flux holding devices are for welding of a joint, both for longitudinally and circumferential joints.

In some applications, including the object support assembly 300, it may be beneficial to provide the welding head 122 with a flux holding device according to the embodiments herein.

In some examples, there is provided a flux holding device 400 for holding flux at a welding head 122 of a SAAM system 100 is described. The flux holding device 400 comprises a frame 410 arranged to hold flux receivable from a flux supply 12 of the SAAM system 100. The flux holding device 400 is adapted to be mounted to the welding head 122, whereby the frame 410 allows flux to be gathered to form a blanket over an arc generated during welding of a weld string 221-225 as the SAAM system 100 is operated. The frame 410 has a base 470, arranged to face a currently deposited weld string during welding. The base 470 can be a lower part of the frame 410, e.g. a portion of the frame 410 closest to any existing preceding layer. The flux holding device 400 is characterized by that the frame 410 comprises a wall portion 420, such as a hatch, that is movable between a first position Pl, in which the wall portion 420 is arranged to protrude from the base 470 and towards any existing preceding weld string, and a second position P2, in which the wall portion 420 is arranged to allow the base 470 to be located in close proximity to, or abut, any existing preceding weld string.

In some examples, the flux holding device 400 is configured, by means of the wall portion 420 and optionally the protruding element 451, to enable the SAAM system 100 to additively manufacture an object 200 built up by non-straight, vertically stacked weld strings.

Hence, Figure 14 shows an example of the flux holding device 400 according to the embodiments herein. Generally, the flux holding device 400 can be configured for holding flux at a welding head 122 of a system 100 as described herein.

The flux holding device 400 comprises a frame 410 that is arranged to hold flux receivable from a flux supply 12 of the system 100. The frame 410 can be in the general shape of a bottomless boat. The frame 410 can be made of a plastic material, a heat resistant plastic material, a ceramic material, a sintered ceramic material or the like. The plastic material can be bakelite, or the like.

The frame 410, i.e. a horizonal cross-section of the frame 410, can be elongated, oval, elliptic, circular, polygonal, rectangular, triangular, or the like. In some examples, any corners of the crosssection can be rounded, such as a rectangle with rounded corners and so on. The flux holding device 400 is adapted to be mounted to the welding head 122, whereby the frame 410 allows flux to be gathered to form a blanket over an arc generated during welding of a weld string as the system 100 is operated.

The flux holding device 400 can be adapted to be connected to a flux supply 12 of the system 100. The frame 410 can comprise a flux inlet 430 configured to receive and fasten the tube 14. Additionally or alternatively, the frame 410 can be configured to receive and fasten the tube 14. In such case, the frame 410 may not necessarily be provided with the flux inlet 430, or the entire upper open face, surrounded by the frame 410, may be considered to embody the flux inlet 430. It may be preferred that the upper open face of the frame is sufficiently large to be able to receive a flow of flux from the tube 14.

A depth of the flux in the frame 410 can thus be determined by the flux inlet 430, when configured to fasten the tube 140, or by an outlet of the tube 14. It can thus be the position, in height, e.g. along z- axis, of the outlet or the flux inlet that ensures that a blanket can be formed at the arc during welding. The position of the outlet or the flux inlet is located below an upper rim of the frame 410.

Furthermore, a height of the frame, e.g. an average height, a minimum height etc., is appropriately adapted to the desired depth of the flux to cover the weld pool. Typically, the provided flux forms a blanket that is 5 mm - 40 mm, 10 mm - 30 mm, 15 - 25 mm, or the like. The outlet or the flux inlet as well as the upper rim of the frame 410 can thus be adapted accordingly.

Shape of the sides of the frame 410 may be determined by the application, e.g. the sides can have different shapes depending on the object to be manufactured.

According to some examples, the flux inlet 430, or an outlet of the tube 14, is located below an upper edge of the frame 410. In this manner, a desired depth B of the flux blanket can be achieved.

The flux holding device 400 can comprise a welding head fastening element 440 for fastening the flux holding device 400 to the welding head 122. Thanks to the welding head fastening element 440, the flux holding device 400 is moved as the welding head 122 is moved, e.g. as controlled by the control unit 140. As an example, the flux holding device 400 can be adapted to be moved in synchrony with the welding head 122, e.g. by means of the welding head fastening element 440. The welding head fastening element 440 is electrically insulating. This means that at least some portion of the fastening element 440 is made of an electrically insulating material.

In some examples, the frame 410 is provided with a protruding element 451 at a lower, front edge

411 of the frame 410. The protruding element 451 is flexible by being able to adapt its shape to said any existing preceding weld string. At the rear edge of the frame 410, a further protruding element can be able to adapt to a weld string currently being deposited. The protruding element can be a brush, or the like. The protruding element, such as brushes, can be made of brass, steel or the like.

Furthermore, the flux holding device 400 can be provided with one or more brushes 451, 452 arranged to brush in front of and/or after the welding pool to at least partially close any existing gap G between the frame 410 and the welding string. For simplicity, it will be referred to as "the brush", while it shall be understood that there can be one or more brushes, e.g. provided at a front edge 411 of the frame 410 and/or a rear edge 412 of the frame 410. The front edge 411 and/or the rear edge 412 are faced along the direction of movement during operation of the welding head 122.

As seen in Figure 15, the brush 451, 452 can have a length that matches the width of the frame 410. It may be preferred that the length of the brush 451 is at least as wide as the weld string and/or that it completely covers a projection of a base of the frame 410, the projection taken perpendicularly to a movement direction of the frame 410. Typically, the length of the brush 451, 452 can be less than or equal to the width of the frame 410. The brush 451, 452 can preferably have length that is equal to or greater than the weld string being deposited. Furthermore, the length of the brush 451, 452 can be greater than two thirds of the width of the frame 410.

The dimensions, such as width, length and height, of the flux holding device, such as the frame 410, can be selected based on operation and/or shape of the object to be manufactured. In particular, the dimensions at the base of the frame 410 can be selected to fit a particular application. As mentioned, the frame 410 can be elongated, e.g. in along the x-axis, i.e. a length along the x-axis is greater than a width along the y-axis. Typical measures can for example be that the width (y-axis) is about 40 mm, the length (x-axis) between 60 and 120 mm. The height can be about 40 - 60 mm.

In the following examples, the wall portion of the flux holding device is a hatch. The wall portion is arranged to be capable of extending the frame away from the inlet, e.g. downwards. In other examples, the wall portion can be a wall element, an additional frame portion, or the like. The wall portion can be flat, curved, bent, or the like, e.g. about a z-axis, as explained below.

Hence, Figure 15 shows that the frame 410 comprises at least one hatch 420, as an example of the wall portion. In some examples, the frame 410 comprises a first hatch 420 and a second hatch 421. In the following, the term "the hatch 420" shall be understood as referring to at least one hatch 420, such as the first and second hatches 420, 421, or the like. The hatch 420 can have a length that extends along at least two thirds of a side of the frame 410. The side can run in the XZ-plane, or almost in the XZ-plane, e.g. at the most at an angle of 45 degrees, 20 degrees, or 10 degrees, to the XZ-plane.

In Figure 16a through Figure 16c, side views of the flux holding device 400 are shown with the hatch 420, placed on a long side of the frame 410. The hatch 420 can be adjustable, slidable, displaceable or the like. In order to give sufficient support for the flux, the hatch 420 can be pushed, e.g. by an operator, down to allow the flux to form the blanket over the weld pool, rather than that the flux falls downwards.

The flux holding device 400 can for example be used when building a tubular member, such as a pipe, a tube or the like. In such scenarios, an object template panel can be used for an inner diameter or an outer diameter, but for the opposite side, i.e. inner or outer, of the tubular member, the flux holding device 400 is useful for supporting the flux.

The hatch 420 is arranged to be movable to and from a first position Pl as shown in Figure 16a. The hatch 420 is thus preferably movable in the vertical direction, e.g. along the z-axis e.g. in the XZ- plane. The hatch 420 can also be movable in the horizontal direction, e.g. along the x-axis and/or along the y-axis. This can e.g. be achieved by that the movement in the vertical direction is performed at an angle, in the XZ-plane, with respect to the z-axis.

In the first position Pl, the hatch 420 extends downwards from the frame 410, e.g. beyond a lower limiting horizontal plane of the frame 410, i.e. at the base of the frame 410. The lower limiting horizontal plane, e.g. in the XY-plane, can be represented by a lower edge of the frame 410. As described further below, the hatch 420 can, when positioned in the first position Pl, prevent at least some flux from escaping the frame, whereby it is ensured that the blanket sufficiently covers the weld pool.

Moreover, the hatch 420 can be arranged to be movable to and from a second position P2 as shown in Figure 16b. The second position P2 can be a neutral position.

In the neutral position P2 illustrated in Figure 16b, the hatch 420 is matched to, such as aligned with, or almost aligned with, with the lower limiting horizontal plane.

In some examples, as shown in Figure 16c and Figure 16d, the flux holding device 400 does not include the adjustable hatch 420. Instead, a portion of the frame, e.g. a flux panel 422, can replace the hatch 420 when located in the first position Pl. In this manner, a flux holding device 400 that can be adapted to a particular application is achieved, while ensuring consistency since the flux holding device 400 is not adjustable, e.g. in terms of the movable hatch.

In some examples, the frame 410 comprises a further wall portion 421 arranged at the frame 410 oppositely to the wall portion 420. Similarly as above, the further wall portion is movable between a further first position Pl, in which the further wall portion 421 extends from the base 470 and towards any existing preceding weld string, and a further second position P2, in which the further wall portion 421 is arranged to allow the base 470 to abut, or be located in close proximity to, any existing preceding weld string.

The wall portion 421, or hatch, can be held in the first and second positions Pl, P2 according to various manners. For example, a length of the wall portion 421, e.g. along the x-axis, can be adapted to cause the front and back edges of the wall portion 421 to be squeezed in the grooves formed by the elements 461 and the frame 410. In this manner, the wall portion 421 can be held in its current position. Alternatively or additionally, the wall portion 421 can have a curvature about a geometric z- axis located outside of the frame, e.g. along and spaced away from the long side of the frame. In this example, the edged of the wall portion 421 pushed outwards at the elements 461. As a result, the friction between the elements 461 and the edged of the wall portion 421 causes the wall portion 421 to be held in place. The curvature of the wall portion is adapted to allow the edges of the wall portion 421 to be inserted into the grooves, while achieving sufficient friction to maintain the wall portion's position in the grooves, e.g. during welding.

Turning again to Figure 15, it can be seen that the hatch 420, 421 is slidable in two tracks 461, such as grooves, or the like.

Figure 17a shows an example, in which the object support assembly 300 and the flux holding device 400 are used, e.g. together, at the same time or the like, during SAAM by means of the system 100. The flux holding device's 400 hatch 420 is positioned in the first position Pl, e.g. the first hatch 420 is located in the first position Pl. The second hatch 421 (not shown in Figure 17a), if existing, can be positioned in the neutral, second position P2.

Figure 17b illustrates an example of the brush 451, 452, wherein strings of the brush 451, 452 have different lengths to make the shape of the brush form fit to the object 200 and possibly also the object support assembly 300. As an example, the brush 451, 452 can have a lower, titled portions facing towards the preceding layer, where e.g. an angle of the tilted portion corresponds to the angle SA. In this manner, the brushes 451, 452 prevents at least some flux from escaping forwards and/or backwards from the flux holding device 400, e.g. in an opening between the frame 410 and a preceding layer 223.

In some examples, the position of the hatch 420 can be adjusted. This means for example that the first position Pl can be selected based on a slope SA, or angle, between the preceding layer 222 and a current layer 223. It is therefore possible to reuse the same flux holding device 400 for at least a range of different shapes of the object 200 to be manufactured. Hence, the flux holding device 400, including the adjustable hatch, can be used in a range of applications.

With a system 100, e.g. setup as described in connection with Figure 17a and Figure 17b, there can thus be provided a method, performed by a system 100, for additively manufacturing an object 200 using SAW. This is illustrated in Figure 18b. In Figure 18b, there is thus illustrated an example of a method, performed by a system 100, for additively manufacturing an object 200 using submerged arc welding. The system 100 comprises a welding head 122 for providing layers of material to additively manufacture the object 200 at a substrate 21, a flux holding device 400 for holding/gathering flux at the welding head 122, a support plate 320 provided with a plurality of ceramic panels 341-344 arranged adjacent to each other and arranged to form an outward surface 348 formed according to at least a portion of a shape, e.g. in at least the z-y plane, of the object 200 to be manufactured. The outward surface 348 faces away from the support plate 320 and towards the object 200 being manufactured. The support plate 320 is arranged at the support 130. The substrate 21 is positioned on a support 130. The system 100 is arranged to move the welding head 122 and the support 130 relatively each other in at least two dimensions, preferably three dimensions.

As mentioned before, the system 100 comprises a support 130 for supporting a substrate 210 at which the object 200 will be manufactured, a welding head 122 for providing layers of material to additively manufacture the object 200, a flux holding device 400 for holding/gathering flux at the welding head 122, and an object support assembly 300, possibly provided with a plurality of ceramic panels arranged adjacent to each other and possibly arranged according to a shape of the object 200 to be manufactured, wherein the object support assembly 300 can be attached to the support 130.

One or more of the following actions may be performed in any suitable order.

Action B110

The system 100, e.g. as controlled by the control unit 140, provides a respective layer 221-225 of the object 200 using the welding head 122 by conveying B120, e.g. in a horizontal plane, the welding head 122 and the flux holding device 400 along the support plate 320 to apply the respective layer 221-225. In this manner, the respective layer is deposited, welded, applied or the like, e.g. by this action and optionally further actions.

Action B120

The system 100, e.g. as controlled by the control unit 140, can convey, such as move, or the like, the welding head 122 and the flux holding device 400 along the support plate 320 to apply the respective layer 211-225. Alternatively or additionally, the system 100, also as controlled by the control unit 140, can move the support 130 to achieve relative movement between the welding head 122 and the support plate 130. Accordingly, the welding head 122 can be moved along a path whose shape is determined based on the shape of the support plate 320. As an example, a horizontal cross-section of the support plate 320 can be in the shape of a wave, then the path along which the welding head 122 is moved describes the wave as seen in horizontal cross-section.

Generally, the path can be translated relatively support plate's 320 cross-sectional shape. A cross- sectional shape refers to a shape of a cross-section, e.g. a contour or periphery of support plate 320 in the cross-section.

In some examples, the conveying B120 of the welding head 122 comprises conveying the welding head 122 based on a shape, i.e. a shape of a horizontal cross-section, of the object 200 to be manufactured.

Action B130

The system 100, e.g. as controlled by the control unit 140, adjusts, e.g. vertically, a vertical distance D between a welding head 122 of the SAAM system 100 and the support 130 based on a layer thickness of the respective layer 221-225 of the object 200.

The distance D can thus be incremented by an amount that corresponds to the layer thickness of the respective layer 221-225 of the object 200.

In some embodiments, a set of actions can comprise the providing B110 of the respective layer, the conveying B120 of the welding head 122 and the adjusting B130 of the distance D. Then, the system 100 can repeat the set of actions.

In some examples of this method, the flux holding device 400 can be according to any example herein. In some examples of this method, the support plate 320 is comprised in an object support assembly 300 according to any one of the examples herein.

In another example, a circular cross section (type pipe) is printed with a static welding head and a rotating turn table acting as support, with the object to be built on top of it. This means that the object to be manufactured can be a pipe or the like. It is beneficial to have a longer frame, i.e. the frame's extension along an angular axis is increased, e.g. in a polar coordinate system having its origo at the center of the pipe, to allow a longer flux blanket. In such example, a general shape of the flux holding device 400 can be curved, bent, or the like, to match the curvature of the object to be manufactured. In turn, the longer flux blanket can secure a more favorable solidification process of the weld string, e.g. by extending the time that the newly deposited weld string is covered by the flux blanket. This also means that the adjustable hatch must be longer to give the flux support, preventing it to fall down the side of the printed part.

Figure 19 and Figure 20 show examples of objects 200 having various shapes. These shapes are considered to be complex, because with the aforementioned techniques for SAAM these objects can be difficult to manufacture. Examples of complex shapes can be shape of hourglass, a tool slide, a compact block, an irregular or regular arch and the like. A complex object can have developable and/or doubly curved surfaces.

Accordingly, Figure 21 shows an example of a system 100 in which the aforementioned complex shapes of objects can be manufactured. The system 100 can be exemplified by any one of the systems shown in Figure 1 to Figure 4.

In this example, a frame assembly 500, e.g. comprising a stack of frames, or the like, is placed on the support 130. In other examples, the frame assembly 500 can be placed on the substrate 21 (not shown in Figure 21). The substrate 21 can, as in at least some other examples, be placed on the support 130.

The frame assembly 500 can include a plurality of frames 501, 502. The frames 501, 502 can be assembled by two or more separable parts. In some examples, each frame of the frames 501, 502 can be achieved by that a respective set of four beams are placed to form e.g. a rectangle where the beams abut each other at the ends. No particular connection between the beams may be required. In some examples, though, the ends of the beams, or at locations elsewhere on the beams, can be provided with a connection element, such as jig-saw puzzle like connection elements, magnetic connections or the like.

In some examples, each frame 501, 502 has the same height, such as a height that is based on the layer thickness of the layers forming the object 200. However, the frames 501, 502 can also have different heights, e.g. when different layers have different thickness. Furthermore, the height of one and the same frame 501, 502 can vary along its periphery, e.g. have different heights at different sides, different height at different locations along one side of the frame, and so on. The heights of the frames 501, 502, or within a single frame, can be different for other reasons, such as to make the frames 501, 502 more versatile, i.e. useable in various applications. Sometimes, the height of the frame(s) 501, 502 is greater than, equal to or less than the layer thickness. When the height of the frame(s) 501, 502 is less than the layer thickness, it may be that two or more frames need to be applied after depositing of a layer, or a weld string. The heights of the frame(s) 501, 502 can be adapted such that the frame assembly 500 is capable of holding a volume of flux that can form a blanket over the weld pool when the plurality layers 221-225 of the object 200 are deposited.

The height of the frame(s) 501, 502 can be 15 mm - 70 mm, 20 mm - 60 mm or the like.

Thanks to the frame assembly 500, there is provided a containment of flux surrounding the object 200 to be manufactured.

The frame assembly 500 can be made of wood, e.g. with metal studs on the side towards the substrate 21 and/or the support 130 in order to protect it from heat generated in the substrate 21 and/or the support 130.

Figure 22 shows an example of a frame 501, 502 of the frame assembly 500. The frame 501, 502 can be assembled by four beams 511-514, such as planks, ribs, or the like. At the corners of the frame 501, 502 jig-saw puzzle cut-outs can be provided to secure the frame from accidental disassembly.

Figure 23 shows another example of how the corners of the frame 501, 502 can be embodied to facilitate formation of the frame 501, 502. In this example, a first beam 512, 513 has a wedge-like cut-out which is configured to receive a corresponding wedge-like cut-out in a second beam 511, 514. In this manner, the cut-outs guide the second beam into position on the first beam, if the first beam is placed at the frame assembly 500 before the second beam. Figure 23a, 23b, 23c can for example depict an end, to the right, of the beam 512. Figure 23a is a top view along the z-axis. Figure 23b is a side view along the x-axis. Figure 23c is a side view along the y-axis. Figure 23d, 23e, 23f can for example depict an end, at the top, of the beam 514. Figure 23d is a top view along the z-axis. Figure 23e is a side view along the y-axis. Figure 23f is a side view along the x-axis. In order to form a frame, there can be a pair of first beams and a pair of second beams, similarly to the example with the jig-saw puzzle cut-outs as shown in Figure 22.

It can be advantageous that the frame assembly 500 includes frames 501, 502 that are decomposable, divisible, separable or the like, since then a further frame can be put on top of a frame already forming part of the frame assembly 500 without a need of temporarily moving the welding head 122 and/or the support 130 to achieve a space between the welding head 122 and the frame assembly 500.

With the system 100 of Figure 21, there is thus provided a method, performed by the system 100, for additively manufacturing an object 200 using SAW. As mentioned, the system 100 comprises a support 130 for supporting a substrate 210 at which the object 200 will be manufactured, a welding head 122 for providing layers of material to additively manufacture the object 200, and a frame assembly 500 for holding/gathering flux at the welding head 122. The frame assembly 500, comprising at least one frame 501, is located on the support 130 and/or on a substrate 21 at which the object 200 is to be manufactured.

The system 100 can comprise, such as include or the like, an assisting moving mechanism 600, such as a robotic arm, a gantry, a linear actuator, a pneumatic actuator, or the like. The assisting moving mechanism 600 can be controllable by the control unit 140. Accordingly, the control unit 140 can be configured to control the moving mechanism, e.g. to provide the frame assembly, etc., as described herein. The assisting moving mechanism 600 can include a gripper, a holder or the like, to facilitate gripping of frames of the frame assembly 500.

Expressed differently, with reference to Figure 18c, there is provided an example of a method, performed by a system 100, for additively manufacturing an object 200 using submerged arc welding. The system 100 comprises a welding head 122 for providing layers of material to additively manufacture the object 200 at a substrate 21, and a frame assembly 500 for holding flux at the welding head 122. The frame assembly 500, comprising at least one frame 501, is positioned on a support 130 and/or on a substrate 21 at which the object 200 is to be manufactured. The substrate 21 is positioned on the support 130. The system 100 is arranged to move the welding head 122 and the support 130 relatively each other in at least two dimensions, preferably along z-axis and along x- or y-axis, more preferably in three dimensions.

One or more of the following actions may be performed in any suitable order. Action C105

The system 100, such as the control unit 140 or the like, can obtain information representing the shape of the object. Preferably, the information can include layer information derived from a digital model of the object (200), such as a computer aided design (CAD) file in any desirable format.

Action C110

The system 100 can provide, such as position, place, locate, put or the like, the frame assembly 500, e.g. at the support 130 and/or the substrate 21, e.g. by use of the assisting moving mechanism 600. The frame assembly 500 can enclose at least a region R of the substrate 210 where the object 200 is to be formed. A height of the frame assembly 500 is sufficiently high for the frame assembly to be filled with flux to an extent that the layer to be deposited can be covered and form a blanked and/or a slag cover during welding of said layer.

Action C130

The system 100, such as the control unit 140 or the like, operates the welding head 122 to form a respective layer 221-225 of the object 200, i.e. said layer mentioned in action C110, based on a shape of the object 200 to be manufactured. The object 200 is formed by a plurality of layers 221-225 that comprises the respective layer 221-225.

Action C130 can be performed for each layer 221-225 of the object 200. Of course, the layers 221- 225 can have the same shape or different shapes from each other.

Action C134

The system 100, such as the control unit 140 or the like, can move the welding head 122 and support 130 relatively each other based on the shape of the object 200 to be manufactured.

Action C136

The system 100, such as the control unit 140 or the like, can provide flux into the frame assembly 500. This can for example mean that the frame assembly 500 is filled with flux, at least to some extent. To some extent can mean that the frame assembly 500 is filled with flux to the extent necessary for the flux to be able to form a blanket over the weld pool during welding.

As the object, e.g. the welded structure, is gaining height the walls will be increased in height to support the flux and the flux in the frame assembly 500 is topped up to be matched, such as aligned, flush, correspond to or the like, with the object being manufactured. This topping up with flux is automatically performed as flux is added for providing the blanket used during the welding process. In some examples, the providing C136 of flux comprises providing an amount of flux that covers the respective layer 221-225.

For at least some of the plurality of layers 221-225 of the object 200, action C140 can be performed.

Action C140

The system 100, such as the control unit 140, or the like, the assisting moving mechanism 600 and/or the like, provides, for at least some of the plurality of layers 221-225 of the object 200, a further frame 502 at, such as on top of, said at least one frame 501, whereby the frame assembly 500 comprises the further frame 502. In this manner, inner walls of the frame assembly 500 form a flux containment. As a result, flux is advantageously confined in the flux containment to enable formation of a blanket during SAW. As an example, as seen in the xy-plane, the layer to be deposited can be enclosed, e.g. at least partially or preferably completely, by the frame assembly 500. Nevertheless, the welding head 122, i.e. at least a portion thereof, is still able to be put into the flux, typically from above.

The system 100, such as the control unit 140, the assisting moving mechanism 600 and/or the like, can provide the further frame 502 by controlling the assisting moving mechanism 600 to place the further frame 502 for inclusion into the frame assembly 500, whereby flux 13, e.g. provided into the volume defined by the frame assembly 500, is allowed to form a blanket over the weld pool.

Moreover, the system 100, such as the control unit 140, the assisting moving mechanism 600 and/or the like, can provide the further frame 502 by assembling, e.g. by means of the assisting moving mechanism 600, the further frame 502 from at least two parts 511, 512, 513, 514 configured to form the further frame 502. Said at least two parts 511, 512, 513, 514 can thus be separable from each other.

In some embodiments, a set of actions can comprise the operating C130 of the welding head 122 and the providing C140 of the further frame 502. Then, the system 100 can repeat the set of actions.

In some embodiments, the repeating of the set of actions includes, e.g. firstly, the operating C130 of the welding head 122 and then, e.g. secondly, performing the providing C140 of the further frame 502. Here, firstly and secondly are used to emphasize the relative relationship in time between the operation C130 and the providing C140.

In view of the method above, it may be noted that the flux, received and accommodated in the frame assembly 500 during the welding process, melts and forms a cover under the weld string and under the weld pool. The solidification of the melted flux, to form the cover, draws heat from the weld string and/or weld pool, which enables a faster solidification of the weld string. In particular, slag under and possibly on the side of the weld pool solidifies and supports the weld string, preventing it from falling down due to gravity.

As previously mentioned, generally in some examples herein, a currently deposited layer may or may not be translated, e.g. in the xy-plane, in relation to a preceding layer. In addition, the currently deposited layer can have a shape, e.g. in a cross-section in the xy-plane, that is the same or different from the preceding layer.

With the examples and embodiments of the method herein, a quality of the object is without, or almost without or with less, defects, such as porosity, lack of fusion and segregations, often occurring in casted objects. A reason behind this is the welding process of submerged arc welding, which has a stable and very penetrating arc that ensures melting of the underlying material, such as layer or substrate. Each weld string also reheats the underlying weld string, which means that weld strings are exposed for a heat treatment that normalizes microstructures within them. As repeated reheating of underlying material occurs using the methods herein, the object formed is also stress relieved. This reduces deformation and at least reduces any residual stresses in the object.

In one example, e.g. with reference to Figure 20, a roof, or arch, can be welded. Figure 20 shows a cross-section in the zy-plane of a plurality of weld strings 221-225. This was achieved thanks to the frame assembly 500 and the method of using the frame assembly 500 in connection with SAAM. In this example, a welding current of 460 A (Ampere), which yielded a deposition rate of 6 kg/h.

Typically, the welding current can be in an interval of 300-1000 A, or the like, depending on the wire diameter and the application.

In general, when performing SAAM, the relative movement of the support 130 and the welding head 122 is performed while observing that an electrical contact with a previously deposited layer can be achieved.

An advantage with the flux holding device 400, when applicable, can be that the volume of flux needed can be reduced as compared to e.g. the free form welding concept.

In some examples of the methods herein, the methods can be performed by a computer, such as the system 100, the control unit 140, and the like, and/or performed manually, e.g. by an operator, a user, or the like. This means that one or more actions can be computer-implemented and/or one or more actions can be performed manually.

Each embodiment, example or feature disclosed herein may, when physically possible, be combined with one or more other embodiments, examples, or features disclosed herein. Even though embodiments of the various aspects have been described above, many different alterations, modifications and the like thereof will become apparent for those skilled in the art. The described embodiments are therefore not intended to limit the scope of the present disclosure.

Claims

1. A method, performed by a system (100), for additively manufacturing an object (200) using submerged arc welding, wherein the system (100) comprises a welding head (122) for providing layers of material to additively manufacture the object (200) at a substrate (21), and a frame assembly (500) for holding flux at the welding head (122), wherein the frame assembly (500), comprising at least one frame (501), is positioned on a support (130) and/or on a substrate (21) at which the object (200) is to be manufactured, wherein the substrate (21) is positioned on the support (130), wherein the system (100) is arranged to move the welding head (122) and the support (130) relatively each other in at least two dimensions, wherein the method comprises: operating (C130) the welding head (122) to form a respective layer (221-225) of the object (200) based on a shape of the object (200) to be manufactured, wherein the object (200) is formed by a plurality of layers (221-225) that comprises the respective layer (221-225), and wherein the method comprises, for at least some of the plurality of layers (221-225) of the object (200): providing (C140) at least one further frame (502) on top of said at least one frame

(501), whereby the frame assembly (500) comprises said at least one further frame (502).

2. The method according to claim 1, wherein the providing (C140) of said at least one further frame

(502) comprises controlling an assisting moving mechanism (600) to place said at least one further frame (502) for inclusion into the frame assembly (500), whereby flux (13) is allowed to form a blanket over the weld pool.

3. The method according to any one of the preceding claims, wherein the method comprises: obtaining (C105) information representing the shape of the object, wherein preferably the information includes layer information derived from a digital model of the object (200).

4. The method according to any one of the preceding claims, wherein the providing (C140) of the further frame (502) comprises assembling the further frame (502) from at least two parts (511, 512, 513, 514) configured to form the further frame (502).

5. The method according to any one of the preceding claims, wherein the operating (C130) comprises: moving (C134) the welding head (122) and support (130) relatively each other based on the shape of the object (200) to be manufactured, and providing (C136) flux into the frame assembly (500).

6. The method according to the preceding claim, wherein the providing (C136) of flux comprises providing an amount of flux that covers the respective layer (221-225).

7. The method according to any one of the preceding claims, wherein the operating (C130) of the welding head (122) is performed for each layer (221-225) of the object (200).

8. The method according to any one of the preceding claims, wherein the method comprises: providing (C110) the frame assembly (500) at the support (130) and/or the substrate (21), wherein the frame assembly (500) encloses at least a region (R) of the substrate (21) where the object (200) is to be formed.

9. The method according to any one of the preceding claims, wherein a set of actions comprises the operating (C130) of the welding head (122) and the providing (C140) of the further frame (502), wherein the method comprises repeating the set of actions.

10. The method according to the preceding claim, wherein the repeating of the set of actions comprises repeating the set of actions by performing the operating (C130) of the welding head (122) and then performing the providing (C140) of the further frame (502).