RU2739931C1 - Method of electron-beam welding of parts from ferromagnetic materials - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to a method for electron-beam welding of parts from ferromagnetic materials and can be used in welding butt joints (longitudinal, circular, annular) joints of parts. Proposed method comprises the following operations: cutting edges of parts for welding, assembly of butt-joints without clearance and demagnetisation of ferromagnetic material in welding zone of parts. Demagnetisation of ferromagnetic material is carried out with an electron beam, which is moved along the edges with displacement from joint by 15–20 mm, and heating of the edges to temperature of material recrystallisation. Then joint is welded.EFFECT: technical result consists in reduction of labour intensity of parts welding and improvement of quality of welded seams.1 cl, 3 dwg

Description

The invention relates to methods for electron beam welding of parts and can be used in electron beam welding of butt (longitudinal, circular, circular) joints of ferromagnetic materials.

There is a known method of electron beam welding of structures, used for welding butt joints of thick plate structures using filler wire [RF patent for invention No. RU 2527112, IPC B23K 15/00, published on 09/10/2015 and publication: "Development of electron beam welding technology steels with residual magnetization "/ N.V. Alexandrov, E. D. Blank, N.V. Vovchenko, S.N. Kurt, S.I. Shekin, A.L. Martyanov, S.V. Ryzhkov // Technologies and equipment "ELS-2014" - St. Petersburg - pp. 141-149].

The method consists in electron-beam welding of steel structures (for example, steel 10KhN3MD), including the assembly of structural elements butt-to-end with a gap between the edges and welding in vacuum with an electron beam scan, while the root and part of the weld section are formed, and the rest of the weld section is formed with the front side is formed by surfacing the filler material.

The closest to the invention in terms of the technical essence and the achieved effect is a method of electron beam welding of ferromagnetic materials using a filler wire [USSR patent for invention No. SU 1779511, IPC B23K 15/00, published on 07.12.1992].

где V_св - скорость сварки, h_сл - высота усиления шва с лицевой стороны стыка, h_k - высота усиления шва с корневой стороны стыка, d_пп - диаметр присадочной проволоки, δ - толщина стыка.The method consists in electron beam welding of ferromagnetic materials with filler material supply, in which parts are welded according to a guaranteed gap in a joint with through penetration and filling the gap with molten metal, the gap is set in proportion to the residual magnetic induction, the filler material speed is set according to the ratio:

where _Vw is the welding speed, h _sl is the height of the seam reinforcement from the front side of the joint, h _k is the height of the seam reinforcement from the root side of the joint, d _pp is the diameter of the filler wire, δ is the thickness of the joint.

The disadvantages of the known methods are:

- the use of filler material and its high consumption during welding;

- high labor intensity due to multipass welding;

- possible defects in the root of the weld - metal leakage due to the presence of a technological gap;

- deflection of the electron beam during welding and the formation of lack of fusion between passes due to the magnetization of the ferromagnetic material.

- it is required to calculate the size of the gap and wire feed speed for high-quality and reliable welding.

Common features for the prototype and the claimed invention are: electron beam welding of parts made of ferromagnetic materials, cutting the edges of parts for welding, butt assembly of parts.

The tasks to be solved by the claimed invention are to reduce the labor intensity of the method of electron beam welding of parts, including large thickness, made of ferromagnetic materials, improve the quality of welded seams and eliminate defects such as lack of fusion, metal outflow from the weld root.

When solving the assigned tasks, the following technical results are achieved:

- improving the quality of welded seams (no leakage of metal from the weld root, increased chemical homogeneity of the weld metal, no lack of fusion);

- saving of filler material, exclusion of the feed mechanism;

- demagnetization of a ferromagnetic material in the welding zone of the parts to be welded by passing an electron beam along the edges at a distance of 15-20 mm from the joint of the parts;

- exclusion of deflection of the electron beam from the joint of parts during welding;

-exclusion of specialized equipment for demagnetizing products before welding.

The technical result is achieved by the fact that in the method of electron beam welding of parts made of ferromagnetic materials, including cutting the edges of parts for welding, assembly of butt parts and welding, according to the invention, butt assembly of parts is carried out without a gap, after assembling the parts, the ferromagnetic material is demagnetized in the part welding zone by performing passage by an electron beam along the edges with an offset from the joint by 15-20 mm and heating the edges to the material recrystallization temperature, after which the joint is welded.

The passage along the edges of the parts to be welded with an electron beam displaced from the joint by 15-20 mm to demagnetize the ferromagnetic material in the welding zone is necessary and sufficient to maintain the visibility of the joint, when this distance is exceeded, the demagnetization of the edges does not occur completely, while during welding the electronic ray.

The claimed technical solution meets the criteria of novelty and inventive step as has distinctive features from the prototype, is characterized by a new set and sequence of essential features, which makes it possible, when using the invention, to solve the set tasks and obtain new technical results in comparison with the identified analogues and the prototype.

The method is illustrated by figures. In fig. 1 shows the body to be welded, fig. 2 - welded edges of body parts prepared for assembly-welding, in Fig. 3 - welded joint after welding parts.

The body was welded (Fig. 1), consisting of two shells 1, 2 and an internal frame 3, each part is made of ferromagnetic material 09G2S, flange 4 is made of ferromagnetic material 17G1S, the thickness of shells, flange and frame is 40 mm. Welded joints 5 and 6.

The welding method was carried out as follows.

Made the machining (cutting) of the welded edges of shells 1, 2 and flange 4 (Fig. 2). Completed the assembly of parts 1, 2, 3 and 4 of the body end-to-end without a gap (Fig. 1). Then, in the main welding modes, along the edges of the welded parts 1, 2 and 3, an electron beam was passed with an offset from the joint of the parts by 15 mm and the edges were heated to the temperature of recrystallization of the ferromagnetic material, as a result, demagnetization of the material in the zone of the welded edges was achieved. After completing these works, welding of joints 5 and 6 was performed, while there was no deflection of the electron beam. After welding, the residual magnetization of joints 5 and 6 was measured (after welding this body, the magnetization was 0.5-1 A / cm).

As a result of welding, welded seams were obtained (Fig. 3), having a high-quality formation of the face of the seam. Before carrying out ultrasonic testing of welded seams using locksmithing, the weld seam was cleaned flush with the base metal. According to the results of ultrasonic testing, the absence of lack of fusion was recorded and the quality of welded seams corresponds to category I OST 92-1114-80.

The claimed method of electron beam welding in comparison with the prototype allows: to reduce the labor intensity of welding by reducing the number of passes; improve the quality of the weld by eliminating the filler material and demagnetizing the ferromagnetic material prior to the butt welding process, which reduces the chemical inhomogeneity of the weld metal; reduce the cost of wire, eliminate the need for a feeder.

Claims (1)

The method of electron beam welding of parts made of ferromagnetic materials, including cutting the edges of parts for welding, assembly of parts butt-weld and welding, characterized in that the assembly of parts is butt-welded without a gap, after assembling the parts, the ferromagnetic material is demagnetized in the welding zone of parts by performing a pass with an electron beam along the edges with an offset from the joint by 15-20 mm and heating the edges to the material recrystallization temperature, after which the joint is welded.

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