CN108356263B - Laser gain material manufacture heat-resisting steel alloy powder of novel martensitic and preparation method thereof - Google Patents

Abstract

The present invention relates to a novel martensitic heat-resistant steel alloy powder for laser additive manufacturing and a preparation method thereof. The novel martensitic heat-resistant steel alloy powder for laser additive manufacturing comprises: carbon 0.05- 0.15%, silicon 0.1-0.4%, manganese 0.3-0.6%, chromium 8.0-12.0%, tungsten 1.5-1.9%, molybdenum 0.1-0.8%, vanadium 0.1-0.3%, tantalum 0.1-0.3%, yttrium 0.1-0.3% and 0.01% to 0.1% cerium, and the balance is iron. The new martensitic heat-resistant steel alloy powder for laser additive manufacturing of the present invention has excellent forming process performance, and the structure formed by laser additive manufacturing is lath martensite+ Dispersed carbide + dispersed oxide, fine and uniform grains, no columnar grain structure, and because metal yttrium is added to the formula of the present invention, yttrium will form Y ₂ O ₃ in the micro-melt pool during laser manufacturing and forming, It solidifies quickly and is dispersed in the forming structure, which effectively controls the type and content of inclusions in the forming structure while ensuring excellent structure density.

Description

Novel martensitic heat-resistant steel alloy powder for laser additive manufacturing and preparation method thereof

technical field

The invention relates to the technical field of alloy powders, in particular to a novel martensitic heat-resistant steel alloy powder for laser additive manufacturing and a preparation method thereof.

Background technique

At present, there are two conventional preparation methods for high-temperature heat-resistant steel, one is hot forming after smelting, and the other is hot isostatic pressing. The former is mainly represented by P91 and P92 heat-resistant steel, but because the precipitated phases are mainly M ₂₃ C ₆ and MX, these two precipitated phases are easy to aggregate and coarsen or transform into coarse Laves phase Z phase under high temperature and long-term service, resulting in High temperature service performance is significantly reduced. ODS heat-resistant steel powder is formed by adding Y ₂ O ₃ powder by hot isostatic pressing. Due to the limitation of equipment, the size of the formed parts is limited, and the forming principle also determines that there will inevitably be a large number of pores, which will affect the mechanical properties of the product. Therefore, a new type of martensitic heat-resistant steel alloy powder dedicated to laser manufacturing is designed, and complex, large-scale and complex heat-resistant steel structural parts can be prepared through laser additive manufacturing.

Contents of the invention

The invention provides a new type of martensitic heat-resistant steel alloy powder for laser additive manufacturing. By optimizing the formula and adding yttrium element to the alloy powder, Y ₂ O ₃ is formed in the micro-melt pool during the laser manufacturing and forming process, and Rapid solidification, dispersed in the formed structure, can effectively control the type and content of inclusions in the formed structure while ensuring excellent structure density.

In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a new type of martensitic heat-resistant steel alloy powder for laser additive manufacturing, in weight percentage, comprising:

Carbon 0.05～0.15%;

Silicon 0.1-0.4%;

Manganese 0.3-0.6%;

Chromium 8.0～12.0%;

Tungsten 1.5～1.9%;

Molybdenum 0.1-0.8%;

Vanadium 0.1-0.3%;

Tantalum 0.1～0.3%;

Yttrium 0.1～0.3%;

Ce 0.01～0.1%;

The balance is iron.

Further, in terms of weight percentage, the new martensitic heat-resistant steel alloy powder includes: 0.1% carbon, 0.3% silicon, 0.5% manganese, 9.1% chromium, 1.5% tungsten, 0.4% molybdenum, 0.2% vanadium, tantalum 0.15%, 0.15% yttrium and 0.05% cerium, and the balance is iron.

Further, in terms of weight percentage, the new martensitic heat-resistant steel alloy powder includes: 0.15% carbon, 0.4% silicon, 0.5% manganese, 11.5% chromium, 1.5% tungsten, 0.6% molybdenum, 0.2% vanadium, tantalum 0.15%, 0.3% yttrium and 0.1% cerium, and the balance is iron.

The present invention also provides a method for preparing the above-mentioned novel martensitic heat-resistant steel alloy powder, which is characterized in that it includes the following process steps: batching→smelting→vacuum atomization→drying→sieving;

details as follows:

(1) Ingredients: ingredients according to the target ingredients;

(2) Melting: Add the prepared metal manganese, metal chromium, metal tungsten, metal molybdenum, metal vanadium and metal iron into the intermediate frequency induction furnace, and heat it to melt it, and add the rest of the prepared raw materials as supplementary materials in order to melt In the alloy solution, control the oxygen content and carbon content to meet the requirements, and adjust the composition before the furnace to pass the furnace;

(3) Vacuum air atomization: the alloy melt finally obtained in step (2) is atomized, and the atomization medium is argon;

(4) drying: adopt far-infrared dryer to dry;

(5) Screening: The powder with a particle size ranging from 150 to 350 meshes is screened out by a powder sieving machine as the finished powder, which is the required new martensitic heat-resistant steel alloy powder.

Further, in the step (2), the carbon block, raw silicon, metal tantalum, metal cerium and metal yttrium in the raw materials are used as supplementary materials, and are sequentially added to the intermediate frequency induction furnace after the rest of the raw materials are melted.

Further, in the step (2), the metal cerium in the raw material is added for deoxidation treatment, and the deoxidation treatment time is 1-2 minutes; after the carbon content and alloy content are controlled to meet the requirements, the metal yttrium in the raw material is added.

Further, in the step (2), the outlet temperature of the alloy solution is 1450-1500°C

Further, the temperature in the intermediate frequency induction furnace is controlled at 1500-1550° C. when feeding the feeding material.

Further, the atomization pressure in the step (3) is 2-10 MPa.

Further, the drying temperature in the step (4) is 200-250°C.

After adopting the above technical scheme, the present invention has the following advantages compared with the prior art: the new martensitic heat-resistant steel alloy powder for laser additive manufacturing of the present invention has excellent forming process performance, and the formed structure of laser additive manufacturing is Lath martensite + dispersed carbide + dispersed oxide, fine and uniform grains, no columnar grain structure; and because metal yttrium is added in the formula of the present invention, yttrium will be in the micro-melt pool during the laser manufacturing and forming process Y ₂ O ₃ is formed, solidified rapidly, and dispersed in the formed structure, which effectively controls the type and content of inclusions in the formed structure while ensuring excellent structure density.

Description of drawings

Accompanying drawing 1 is the metallographic structure diagram that the embodiment of the present invention 1 obtains;

Accompanying drawing 2 is the metallographic structure diagram that the embodiment of the present invention 2 obtains;

Accompanying drawing 3 is the metallographic structure diagram that the embodiment of the present invention 3 obtains;

Accompanying drawing 4 is the metallographic structure chart that the embodiment 4 of the present invention obtains.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

The invention provides a novel martensitic heat-resistant steel alloy powder for laser additive manufacturing, which comprises: 0.05-0.15% carbon, 0.1-0.4% silicon, 0.3-0.6% manganese, and 8.0-12.0% chromium in weight percentage , 1.5-1.9% of tungsten, 0.1-0.8% of molybdenum, 0.1-0.3% of vanadium, 0.1-0.3% of tantalum, 0.1-0.3% of yttrium and 0.01-0.1% of cerium, and the balance is iron.

The present invention also provides a method for preparing the above-mentioned novel martensitic heat-resistant steel alloy powder, which includes the following process steps: batching→smelting→vacuum atomization→drying→sieving;

details as follows:

(1) Ingredients: Metal manganese, metal chromium, metal tungsten, metal molybdenum, metal vanadium, metal iron, carbon block, raw silicon, metal tantalum, metal cerium and metal yttrium are used as raw materials to make ingredients according to the target composition.

(2) Melting:

(2.1) Add the prepared metal manganese, metal chromium, metal tungsten, metal molybdenum, metal vanadium and metal iron into the intermediate frequency induction furnace, and heat it to melt, carbon block, raw material silicon, metal tantalum, metal cerium and metal yttrium as a supplement.

(2.2) Add the configured carbon block, raw silicon and metal tantalum into the molten alloy solution in sequence.

(2.3) Deoxidation treatment is carried out by adding metal cerium, and the time of deoxidation treatment is 1-2 minutes.

(2.4) After controlling the carbon content and alloy content to meet the requirements, add metal yttrium, and adjust the composition before the furnace to pass the furnace, and the furnace temperature is 1450-1500 °C.

Preferably, the temperature in the intermediate frequency induction furnace is controlled at 1500-1550° C. when the supplementary material is added. In step (2.4), thermal insulation measures are taken for the middle leakage bag.

(3) Vacuum air atomization: atomize the alloy melt finally obtained in step (2), the atomization medium is argon, and the atomization pressure is 2-10 MPa.

(4) Drying: use a far-infrared dryer with a drying temperature of 200-250°C.

(5) Screening: The powder with a particle size ranging from 150 to 350 meshes is screened out by a powder sieving machine as the finished powder, which is the required new martensitic heat-resistant steel alloy powder.

The sources of the raw materials used in the present invention are not limited and are commercially available.

Using the standard of GB/T223 "Chemical Analysis Methods of Iron and Steel and Alloys", the composition of the new martensitic heat-resistant steel alloy powder prepared by the above steps is tested. The test results are, in weight percentage, including: carbon 0.05～0.15 %, silicon 0.1-0.4%, manganese 0.3-0.6%, chromium 8.0-12.0%, tungsten 1.5-1.9%, molybdenum 0.1-0.8%, vanadium 0.1-0.3%, tantalum 0.1-0.3%, yttrium 0.1-0.3% and Cerium 0.01-0.1%, the balance is iron.

After cooling the above-mentioned new martensitic heat-resistant steel alloy powder to room temperature, the laser additive manufacturing method is used to manufacture parts with complex flow channel structures. The steps are as follows:

(1) Three-dimensional modeling, use image layering software for slice layering, and use path planning software for forming path design.

(2) Select different process parameters, analyze the influence of the process on the structure and performance, propose the best process parameters, and print parts according to the pre-established forming path.

(3) Perform surface cleaning, stress relief annealing and other post-treatments to obtain parts with good quality.

After slicing, grinding, polishing, and corrosion of the parts obtained above, the metallographic structure is observed. It can be seen that the structure is dense, the grains are fine and uniform, and there is no columnar grain structure. The formed structure is lath martensite + dispersed carbonization substance + dispersed oxide, fine Y ₂ O ₃ precipitates dispersed in the tissue can be seen in the tissue.

The effect of each element in the novel martensitic heat-resistant steel alloy powder of the present invention is as follows:

(1) Silicon element: mainly used to improve the forming process of alloy powder.

(2) Manganese element: reduce the A ₁ point and promote the precipitation of M ₆ C.

(3) Chromium element: used to ensure corrosion resistance and high temperature oxidation resistance. Chromium is also a ferrite forming element, which is beneficial to obtain martensitic structure after quenching to improve mechanical properties.

(4) Tungsten element: It is an important element that affects the strength of heat-resistant steel and the ductile-brittle transition temperature DBTT. When the required high-temperature strength can be guaranteed, since tungsten can also promote the precipitation of a large amount of Laves phase, it will significantly deteriorate the toughness. Therefore, It is also necessary to control the tungsten content to minimize the possibility of Laves phase precipitation during forming.

(5) Molybdenum element: It is used to improve the high-temperature strength through the precipitation of M ₆ C. At the same time, the molybdenum element can also play a role in solid solution strengthening, preventing the growth of austenite grains by affecting the diffusion.

(6) Vanadium and tantalum elements: used to form MX particles at higher temperatures, and VN and TaC are precipitated at lower temperatures. These fine and dispersed carbide particles can pin dislocations, which can improve mechanical properties and High temperature creep properties.

(7) Cerium element: used for deoxidation in alloy melting furnaces, it has excellent deoxidation effect, thereby controlling the oxygen content, avoiding the oxidation of yttrium element added later, and improving the yield.

(8) Yttrium element: It is used to react with oxygen in the micro-melting pool metallurgy process in the process of additive manufacturing, and form fine and dispersed Y ₂ O ₃ in situ, improve the thermal stability of lath martensite, and improve high-temperature service performance .

The following are preferred embodiments:

Example 1

First, the ingredients are prepared according to the following proportions, including 0.07% carbon, 0.2% silicon, 0.5% manganese, 8.0% chromium, 1.5% tungsten, 0.1% molybdenum, 0.15% vanadium, 0.15% tantalum, 0.1% yttrium and 0.02% cerium, the balance is iron.

Put the prepared metal manganese, metal chromium, metal tungsten, metal molybdenum, metal vanadium and metal iron into the intermediate frequency induction furnace, and heat it to melt, carbon block, raw material silicon, metal tantalum, metal cerium and metal yttrium as supplementary materials Add, the temperature in the intermediate frequency induction furnace is controlled at 1520 ℃ when adding supplementary material. The configured carbon block, raw silicon and metal tantalum are sequentially added to the molten alloy solution. Deoxidation treatment is carried out by adding metal cerium, and the time of deoxidation treatment is 1min. After the carbon content and alloy content are controlled to meet the requirements, metal yttrium is added, and the composition is adjusted before the furnace to pass the furnace, and the furnace temperature is 1460°C. The alloy melt is atomized to prepare alloy powder, the atomization medium is argon, and the atomization pressure is 4MPa. The alloy powder is dried with a far-infrared dryer, and the drying temperature is 210°C. Then, the powder with a particle size ranging from 100 mesh to 350 mesh is screened out by a powder sieving machine as the finished powder.

After the above-mentioned finished powder is cooled to room temperature, the laser additive manufacturing method is used to make parts with complex flow channel structures.

After the above-mentioned parts are sliced, ground, polished and corroded, the metallographic structure is observed, and the obtained metallographic structure picture is shown in Figure 1. As can be seen from Figure 1, the parts structure prepared in Example 1 of the present invention Dense, fine and uniform grains, no columnar grain structure, the formed structure is lath martensite + dispersed carbide + dispersed oxide, and fine Y ₂ O ₃ precipitates dispersed in the structure can be seen in the structure.

Samples were taken from the components prepared in Example 1 of the present invention and tested for mechanical properties. The test results are shown in Table 1. Table 1 shows the composition of the new martensitic heat-resistant steel alloy powder provided by various embodiments of the present invention and the test results of the mechanical properties of the obtained complex flow channel structure.

Example 2

According to the method described in Example 1, parts with complex flow path structures are prepared. The difference from Example 1 is that the ingredients in this example are formulated according to the following target components, including 0.1% carbon, 0.3% silicon, 0.5% manganese, 9.1% chromium, 1.5% tungsten, 0.4% molybdenum, 0.2% vanadium, 0.15% tantalum, 0.15% yttrium and 0.05% cerium, the balance being iron. During the preparation process of the new martensitic heat-resistant steel alloy powder, the temperature in the intermediate frequency induction furnace was controlled at 1500°C when the feeding material was added, the furnace temperature was 1450°C, the atomization pressure was 6MPa, and the drying temperature of the far-infrared dryer was 230°C. Then, the powder with a particle size ranging from 100 mesh to 350 mesh is screened out by a powder sieving machine as the finished powder. Accompanying drawing 2 is the metallographic structure picture of the parts with complex channel structure prepared in Example 2 of the present invention.

According to the method described in Example 1, samples were taken from the parts prepared in Example 2 of the present invention and tested for mechanical properties. The test results are shown in Table 1.

Example 3

According to the method described in Example 1, parts with complex flow path structures are prepared. The difference from Example 1 is that the ingredients in this example are formulated according to the following target components, including 0.11% carbon, 0.4% silicon, 0.5% manganese, 9.1% chromium, 1.5% tungsten, 0.4% molybdenum, 0.2% vanadium, 0.15% tantalum, 0.3% yttrium and 0.05% cerium, the balance being iron. During the preparation process of the new martensitic heat-resistant steel alloy powder, the temperature in the intermediate frequency induction furnace is controlled at 1540°C when the supplementary material is added, the furnace temperature is 1480°C, the atomization pressure is 6.5MPa, and the drying temperature of the far-infrared dryer is 250°C. Then, the powder with a particle size ranging from 100 mesh to 350 mesh is screened out by a powder sieving machine as the finished powder. Accompanying drawing 3 is the metallographic structure picture of the parts with complex channel structure prepared in Example 3 of the present invention.

According to the method described in Example 1, samples were taken from the parts prepared in Example 3 of the present invention and tested for mechanical properties. The test results are shown in Table 1.

Example 4

According to the method described in Example 1, parts with complex flow path structures are prepared. The difference from Example 1 is that the ingredients in this example are formulated according to the following target components, including 0.15% carbon, 0.4% silicon, 0.5% manganese, 11.5% chromium, 1.5% tungsten, 0.6% molybdenum, 0.2% vanadium, 0.15% tantalum, 0.3% yttrium and 0.1% cerium, the balance being iron. During the preparation process of the new martensitic heat-resistant steel alloy powder, the temperature in the intermediate frequency induction furnace was controlled at 1550°C when the feeding material was added, the furnace temperature was 1500°C, the atomization pressure was 8MPa, and the drying temperature of the far-infrared dryer was 235°C. Then, the powder with a particle size ranging from 100 mesh to 350 mesh is screened out by a powder sieving machine as the finished powder. Accompanying drawing 4 is the metallographic structure picture of the parts with complex channel structure prepared in Example 4 of the present invention.

According to the method described in Example 1, samples were taken from the parts prepared in Example 4 of the present invention and tested for mechanical properties. The test results are shown in Table 1.

Table 1

It can be seen from Table 1 that the novel martensitic heat-resistant steel alloy powder for laser additive manufacturing of the present invention has excellent forming process performance, and the complex runner structure prepared by laser additive manufacturing has better mechanical properties, and the formed structure It is lath martensite + dispersed carbide + dispersed oxide, with dense structure, fine and uniform grains, and no columnar grain structure. Due to the addition of metal yttrium in the formula of the present invention, yttrium will form _Y2O3 in the micro _- melt pool during the laser manufacturing and forming process, and quickly solidify and disperse in the formed structure, which is effective while ensuring excellent structure density. The type and content of inclusions in the formed structure are controlled.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. a kind of laser gain material manufacture heat-resisting steel alloy powder of novel martensitic, which is characterized in that by weight percentage, institute State the composition of the heat-resisting steel alloy powder of novel martensitic are as follows:

Carbon 0.05~0.15%；

Silicon 0.1~0.4%；

Manganese 0.3~0.6%；

Chromium 8.0~12.0%；

Tungsten 1.5~1.9%；

Molybdenum 0.1~0.8%；

Vanadium 0.1~0.3%；

Tantalum 0.1~0.3%；

Yttrium 0.1~0.3%；

Cerium 0.01~0.1%；

Surplus is iron.

2. a kind of laser gain material manufacture heat-resisting steel alloy powder of novel martensitic according to claim 1, feature exist In, by weight percentage, the composition of the heat-resisting steel alloy powder of novel martensitic are as follows: carbon 0.1%, silicon 0.3%, manganese 0.5%, Chromium 9.1%, tungsten 1.5%, molybdenum 0.4%, vanadium 0.2%, tantalum 0.15%, yttrium 0.15% and cerium 0.05%, surplus are iron.

3. a kind of laser gain material manufacture heat-resisting steel alloy powder of novel martensitic according to claim 1, feature exist In, by weight percentage, the composition of the heat-resisting steel alloy powder of novel martensitic are as follows: carbon 0.15%, silicon 0.4%, manganese 0.5%, Chromium 11.5%, tungsten 1.5%, molybdenum 0.6%, vanadium 0.2%, tantalum 0.15%, yttrium 0.3% and cerium 0.1%, surplus are iron.

4. a kind of method for being used to prepare the heat-resisting steel alloy powder of novel martensitic as described in any one of claims 1 to 3, It is characterized in that, comprises the following steps that: ingredient → melting → vacuum aerosolization → drying → screening；

It is specific as follows:

(1) ingredient: ingredient is carried out according to target component；

(2) intermediate frequency furnace melting: is added in the manganese metal prepared, crome metal, tungsten, metal molybdenum, vanadium metal and metallic iron In, electrified regulation makes its fusing, sequentially adds in the alloy solution of fusing using remaining configured raw material as feed supplement, stokehold tune After being made into division lattice, come out of the stove；

(3) vacuum aerosolization: the finally obtained alloy molten solution of step (2) is atomized, atomizing medium is argon gas；

(4) dry: to be dried using coated infrared drier；

(5) sieve: sifting out particle size range by sieving machine is 150~350 mesh powders as finished powder, as required novel horse The heat-resisting steel alloy powder of family name's body.

5. according to the method described in claim 4, it is characterized by: in the step (2), by raw material carbon block, raw silicon, Metal tantalum, metallic cerium and metallic yttrium sequentially add in the intermediate frequency furnace as feed supplement, and after the fusing of remaining raw material.

6. according to the method described in claim 5, it is characterized by: passing through the metallic cerium being added in raw material in the step (2) Deoxidation treatment is carried out, the time of deoxidation treatment is 1~2min；After control carbon content and alloy content reach requirement, then add original Metallic yttrium in material.

7. according to the method described in claim 4, it is characterized by: in the step (2), the tapping temperature of alloy solution is 1450~1500 DEG C.

8. according to the method described in claim 4, it is characterized by: temperature control when feed supplement in the intermediate frequency furnace is added At 1500 ~ 1550 DEG C.

9. according to the method described in claim 4, it is characterized by: the atomizing pressure in the step (3) is 2~10MPa.

10. according to the method described in claim 4, it is characterized by: the drying temperature in the step (4) is 200~250 ℃。