阅读说明：本技术 一种gh4099镍基合金构件的激光沉积成形工艺方法 (Laser deposition forming process method of GH4099 nickel-based alloy component ) 是由 许旭鹏 钱远宏 李志勇 于 2020-11-24 设计创作，主要内容包括：本发明属于金属增材制造及高温合金技术领域,尤其涉及一种GH4099镍基合金构件的激光沉积成形工艺方法。步骤如下：将GH4099镍基合金制成合金粉末,干燥处理；选取对沉积成形的基板,进行预处理；设置激光沉积成的工艺参数并进行合金构件的沉积成形,得到合金构件；对得到合金构件进行热处理,得到外形尺寸、理化性能均合格的GH4099镍基合金构件。本发明通过对粉末的合金成分优化,实现了GH4099镍基合金在激光增材制造过程中的质量稳定控制,有效避免了晶间开裂；通过合理调控激光沉积工艺参数,实现激光功率与扫描速度的有效匹配,提高沉积层与基体制件的冶金结合质量,减少由于急速加热/冷却产生的热应力,保证产品内部质量。(The invention belongs to the technical field of metal additive manufacturing and high-temperature alloy, and particularly relates to a laser deposition forming process method of a GH4099 nickel-based alloy component. The method comprises the following steps: preparing GH4099 nickel-based alloy into alloy powder, and drying; selecting a substrate for deposition forming, and carrying out pretreatment; setting technological parameters of laser deposition and carrying out deposition forming on the alloy component to obtain the alloy component; and carrying out heat treatment on the obtained alloy component to obtain the GH4099 nickel-based alloy component with qualified overall dimension and physical and chemical properties. According to the invention, the alloy components of the powder are optimized, so that the stable quality control of the GH4099 nickel-based alloy in the laser additive manufacturing process is realized, and intergranular cracking is effectively avoided; by reasonably regulating and controlling the laser deposition process parameters, the effective matching of the laser power and the scanning speed is realized, the metallurgical bonding quality of a deposition layer and a substrate workpiece is improved, the thermal stress generated by rapid heating/cooling is reduced, and the internal quality of a product is ensured.)

1. A laser deposition forming process method of a GH4099 nickel-based alloy component is characterized by comprising the following steps:

s1) preparing GH4099 nickel-based alloy into alloy powder, and drying;

s2) selecting a deposition-formed substrate, and preprocessing the substrate;

s3) constructing a laser deposition forming model of the alloy component to be formed, and forming the powder obtained in S2) by adopting a laser deposition forming process method to obtain the alloy component;

s4) carrying out heat treatment on the alloy member obtained in the step S3) to obtain the GH4099 nickel-based alloy member with qualified overall dimension and physical and chemical properties.

2. The method as claimed in claim 1, wherein the GH4099 nickel-based alloy in S1) is alloy bar, and the alloy bar is prepared into spherical powder for laser deposition by a rotary electrode atomization method, wherein the particle size of the spherical powder is 75-185 μm; the sphericity of the powder is not less than 0.95.

3. The method according to claim 2, wherein the components of the GH4099 nickel-based alloy are, by mass: 17-20% of Cr, less than or equal to 0.06% of C, 3.5-4.3% of Mo3, 1.5-2.3% of Al, 5.5-8% of Co, less than or equal to 0.5% of Si, less than or equal to 0.4% of Mn, 5-7% of W, 1.1-1.6% of Ti, and the balance of Ni and inevitable impurities.

4. The method as claimed in claim 1, wherein the specific process of the pretreatment in S2) is as follows: and grinding the surface of the substrate, wherein the roughness of the surface of the substrate is Ra10-Ra13, and cleaning the surface of the substrate by using acetone or ethanol cleaning solution to remove surface stains and impurities.

5. The method as claimed in claim 1, wherein the step of S3) comprises the steps of:

s3.1) the laser deposition process parameters are as follows: the laser power is 1600W-2500W, the scanning speed is 700mm/min-900mm/min, the diameter of a light spot is 3mm-6mm, the powder feeding speed is 5-20g/min, the flow of a powder feeder is 9-10L/h, the powder feeding gas is argon or nitrogen, and the deposition layering thickness is 0.5mm-1.5 mm;

s3.2) carrying out reciprocating scanning according to a set laser scanning mode, wherein the included angle between the upper layer and the lower layer of scanning tracks is 45-90 degrees, the lap joint rate of the matching of adjacent scanning tracks is 15-50 percent, and carrying out deposition forming on the alloy component to obtain the alloy component.

6. The method of claim 5, wherein the laser scanning is a checkerboard scan, and the scanning path within the checkerboard scan is a one-way reciprocal zig-zag scan.

7. The method of claim 5, wherein the oxygen content in the forming cavity during the deposition process is controlled to be less than 1500 ppm; the laser is a fiber laser.

8. The method according to claim 1, wherein the heat treatment in S4) is a solution + aging treatment, and the solution treatment process is as follows: keeping the temperature at 1120-1150 ℃ for 1-2.5 h, and air-cooling or air-cooling to room temperature;

the aging treatment method comprises the following steps: after the solution treatment, the alloy component is kept warm for 8-14 h at the temperature of 800-950 ℃ and cooled to room temperature by air.

9. The method of claim 1, wherein the alloy member has a tensile strength of 800MPa or more, a yield strength of 600MPa or more, and an elongation of 14% or more at 700 ℃;

the tensile strength is more than or equal to 320MPa, the yield strength is more than or equal to 260MPa, and the elongation is more than or equal to 12% at 900 ℃.

10. A GH4099 nickel-base alloy component prepared by the method of any one of claims 1-9.

Technical Field

The invention belongs to the technical field of metal additive manufacturing and high-temperature alloy, and particularly relates to a laser deposition forming process method of a GH4099 nickel-based alloy component.

Background

GH4099 is a typical precipitation hardening type nickel-based wrought superalloy, has high heat strength, can be used for a long time at 900 ℃, and can reach 1000 ℃ in a short time. The alloy has stable structure and good cold and hot processing forming and welding process performance, and is suitable for manufacturing high-temperature plate bearing welding structural parts such as an aircraft engine combustion chamber, an afterburner and the like. However, in aerospace equipment manufacturing engineering application, the alloy has poor casting performance and high processing difficulty, has high hot crack sensitivity in the welding process, and is easy to crack among crystals to generate internal cracks. The product performance is seriously influenced, and the existing manufacturing means is difficult to meet the production requirement.

In recent years, with the development of a coaxial powder feeding additive manufacturing technology, near-net forming of a high-alloying high-melting-point high-hardness material is realized by adopting a laser deposition forming (LMD) technical means, and the method becomes a research and application hotspot in the field of high-temperature alloy manufacturing. The GH4099 nickel-based alloy has high alloying degree and large difference of melting points of alloy elements, and in the processes of high-power laser deposition and high-frequency melting solidification, low-melting-point elements are easy to be subjected to grain boundary segregation or form eutectic phases with low melting points in the deposition and condensation processes, and phase segregation is easy to cause cracking. According to the invention, by optimizing and adjusting chemical components of raw materials, reasonably designing a laser deposition process, carrying out process heat treatment on a workpiece and the like, interface bonding and metallurgical quality of few deposited layers can be effectively realized, further grain boundary heat cracking is eliminated, and the performance of the workpiece is ensured.

Disclosure of Invention

The invention discloses a laser deposition forming process method of a GH4099 nickel-based alloy component, which aims to solve any of the technical problems and other potential problems in the prior art.

In order to solve the technical problems, the technical scheme of the invention is as follows: a laser deposition forming process method of a GH4099 nickel-based alloy component specifically comprises the following steps:

s1) preparing GH4099 nickel-based alloy into alloy powder, and drying;

s2) selecting a deposition-formed substrate, and preprocessing the substrate;

s3) constructing a laser deposition forming model of the alloy component to be formed, and forming the powder obtained in S2) by adopting a laser deposition forming process method to obtain the alloy component;

s4) carrying out heat treatment on the alloy member obtained in the step S3) to obtain the GH4099 nickel-based alloy member with qualified overall dimension and physical and chemical properties.

Further, the GH4099 nickel-based alloy in S1) is an alloy bar, the alloy bar is used for preparing spherical powder for laser deposition by a rotary electrode atomization method, and the particle size of the spherical powder is 75-185 μm; the sphericity of the powder is not less than 0.95.

Further, the GH4099 nickel-based alloy comprises the following components in percentage by mass: 17-20% of Cr, less than or equal to 0.06% of C, 3.5-4.3% of Mo, 1.5-2.3% of Al, 5.5-8% of Co, less than or equal to 0.5% of Si, less than or equal to 0.4% of Mn, 5-7% of W, 1.1-1.6% of Ti, and the balance of Ni and inevitable impurities.

Further, the specific process of the pretreatment in S2) is as follows: grinding the surface of the substrate to the roughness of Ra10-Ra13, and cleaning with acetone or ethanol cleaning solution to remove surface stains and impurities.

Further, the substrate is a stainless steel plate, a carbon steel plate or a high-temperature alloy plate,

further, the step S3) includes the following steps:

s3.1) the laser deposition process parameters are as follows: the laser power is 1600W-2500W, the scanning speed is 700mm/min-900mm/min, the diameter of a light spot is 3mm-6mm, the powder feeding speed is 5-20g/min, the flow of a powder feeder is 9-10L/h, the powder feeding gas is argon or nitrogen, and the deposition layering thickness is 0.5mm-1.5 mm;

s3.2) the laser scanning mode is checkerboard scanning, the scanning mode in the checkerboard scanning mode is single-layer strip reciprocating scanning, the included angle between the upper layer scanning track and the lower layer scanning track is 45-90 degrees, the lap joint rate of the matching of the adjacent scanning tracks is 15-50 percent, and the alloy component is obtained by deposition forming.

Further, the oxygen content in the forming cavity in the deposition process is controlled below 1500 ppm; the laser is a fiber laser.

Further, the heat treatment in S4) is a solution treatment plus aging treatment method, and the solution treatment process method includes: preserving the heat of the heat treatment furnace at 1120-1150 ℃ for 1-2.5 h, and air-cooling or air-cooling to room temperature;

the aging treatment method comprises the following steps: after the solution treatment, the workpiece is kept warm for 8 to 14 hours in a heat treatment furnace at the temperature of between 800 and 950 ℃, and then is cooled to room temperature by air.

Further, the tensile strength of the alloy component at 700 ℃ is more than or equal to 800MPa, the yield strength is more than or equal to 600MPa, and the elongation is more than or equal to 14%;

the tensile strength is more than or equal to 320MPa, the yield strength is more than or equal to 260MPa, and the elongation is more than or equal to 12% at 900 ℃.

The GH4099 nickel-based alloy component is prepared by the method.

The laser additive manufacturing method has the beneficial effects that by adopting the technical scheme, the quality of the GH4099 nickel-based alloy in the laser additive manufacturing process is stably controlled by optimizing the alloy components of the powder, and intergranular cracking is effectively avoided; by reasonably regulating and controlling the laser deposition process parameters, the effective matching of the laser power and the scanning speed is realized, the metallurgical bonding quality of a deposition layer and a substrate workpiece is improved, the thermal stress generated by rapid heating/cooling is reduced, and the internal quality of a product is ensured.

Description of the drawings:

FIG. 1 is a flow chart of a laser deposition forming process method of a GH4099 nickel-based alloy component.

FIG. 2 is a schematic view of the microstructure of the laser deposited powder of the present invention.

Fig. 3 is a schematic view of the metallographic structure (as-deposited state) of the member produced in example 1 of the present invention. FIG. 3a is a transverse pattern; fig. 3b is a vertical organization.

FIG. 4 is a graph showing room-temperature tensile properties (as heat-treated) of a formed article of the member produced in example 1 of the present invention.

FIG. 5 is a schematic view showing a metallographic structure (heat-treated state) of a member produced in example 2 of the present invention. FIG. 5a is a transverse pattern; fig. 5b is a vertical organization.

FIG. 6 is a graphical representation of the tensile properties at 700 ℃ of the component produced in example 2 according to the invention.

Fig. 7 is a schematic drawing of the tensile fracture morphology of the component prepared in example 2 of the present invention, where fig. 7a is 500#, and fig. 7b is 1000 #.

FIG. 8 is a graph showing the tensile properties at 900 ℃ of the member prepared in example 3 of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

As shown in FIG. 1, the laser deposition forming process method of the GH4099 nickel-based alloy component of the invention specifically comprises the following steps:

s1) preparing GH4099 nickel-based alloy into alloy powder, and drying;

s2) selecting a deposition-formed substrate, and preprocessing the substrate;

s3) constructing a laser deposition forming model of the alloy component to be formed, and forming the powder obtained in S2) by adopting a laser deposition forming process method to obtain the alloy component;

s4) carrying out heat treatment on the alloy member obtained in the step S3) to obtain the GH4099 nickel-based alloy member with qualified overall dimension and physical and chemical properties.

The GH4099 nickel-based alloy in the S1) is an alloy bar, the alloy bar is used for preparing spherical powder for laser deposition by a rotary electrode atomization method, and the particle size of the powder is 75-185 microns; the sphericity of the powder is not less than 0.95.

The GH4099 nickel-based alloy comprises the following components in percentage by mass: 17-20% of Cr, less than or equal to 0.06% of C, 3.5-4.3% of Mo, 1.5-2.3% of Al, 5.5-8% of Co, less than or equal to 0.5% of Si, less than or equal to 0.4% of Mn, 5-7% of W, 1.1-1.6% of Ti, and the balance of Ni and inevitable impurities.

The specific process of the pretreatment in the step S2) is as follows: grinding the surface of the substrate to ensure that the surface of the substrate has certain roughness (Ra10-Ra13), and cleaning with acetone or ethanol cleaning solution to remove surface stains and impurities.

The substrate is a stainless steel plate, a carbon steel plate or a high-temperature alloy plate.

The S3) concrete steps are:

s3.1) the laser deposition process parameters are as follows: the laser power is 1600W-2500W, the scanning speed is 700mm/min-900mm/min, the diameter of a light spot is 3mm-6mm, the powder feeding speed is 5-20g/min, the flow of a powder feeder is 9-10L/h, the powder feeding gas is argon or nitrogen, and the deposition layering thickness is 0.5mm-1.5 mm;

s3.2) the laser scanning mode is checkerboard scanning, the scanning mode in the checkerboard scanning mode is single-layer strip reciprocating scanning, the included angle between the upper layer scanning track and the lower layer scanning track is 45-90 degrees, the lap joint rate of the matching of the adjacent scanning tracks is 15-50 percent, and the alloy component is obtained by deposition forming.

The oxygen content in the forming cavity in the deposition process is controlled below 1500 ppm; the laser is a fiber laser.

The heat treatment in the step S4) is a solution treatment and aging treatment method, and the solution treatment process method includes: preserving the heat of the heat treatment furnace at 1120-1150 ℃ for 1-2.5 h, and air-cooling or air-cooling to room temperature;

the aging treatment method comprises the following steps: after the solution treatment, the workpiece is kept warm for 8 to 14 hours in a heat treatment furnace at the temperature of between 800 and 950 ℃, and then is cooled to room temperature by air.

The tensile strength of the alloy component is more than or equal to 800MPa at 700 ℃, the yield strength is more than or equal to 600MPa, and the elongation is more than or equal to 14%;

the tensile strength is more than or equal to 320MPa, the yield strength is more than or equal to 260MPa, and the elongation is more than or equal to 12% at 900 ℃.

The GH4099 nickel-based alloy component is prepared by the method.

Example 1:

a laser deposition process of nickel-base alloy powder, comprising the steps of:

GH4099 nickel-based alloy bar is adopted to prepare powder for laser deposition by a rotary electrode atomization method, the particle size distribution of the powder is 75-185 mu m, and the powder comprises the following chemical components in percentage by weight: 17.8% of Cr, 0.045% of C, 3.7% of Mo, 1.9% of Al, 6.79% of Co, 0.26% of Si, 0.024% of Mn, 6.8% of W, 1.58% of Ti and the balance of Ni and inevitable impurities, and drying the powder at 200 ℃ for 2 h;

a 45 steel plate is used as a deposition substrate, and the surface of the processed substrate is cleaned by acetone after being ground;

setting the movement path track of the laser and the powder feeding shaft, and carrying out deposition forming by adopting a checkerboard scanning mode;

the forming process parameters are as follows: the laser power is 1900W, the scanning speed is 700mm/min, the diameter of a light spot is 3.5mm, the powder feeding speed is 15g/min, the flow rate of a powder feeder is 10L/h, the powder feeding gas is argon, the deposition layering thickness is 0.5mm, the pass overlapping rate is 25%, and the oxygen content is controlled below 1200ppm in the forming process;

and after the forming is finished, performing heat treatment on the workpiece, wherein the heat treatment system is 1120 +/-10 ℃, preserving heat for 2 hours, performing air cooling, preserving heat for 8 hours at 800 +/-10 ℃, and performing air cooling.

As shown in fig. 2, which is a scanning photograph of the laser deposited powder after the drying process, it can be seen that the surface of the powder after the drying process is relatively smooth, and there is no obvious satellite powder and powder adhesion phenomenon, which is beneficial to the improvement of powder fluidity, and thus, is beneficial to the powder transportation in the coaxial powder feeder.

As shown in FIG. 3, the optical micrograph of the sample deposited after laser deposition of the invention shows that the metallographic structure has clear grain boundary, fine grains, uniform tissue distribution and no defects such as cracks, pores, sand holes and the like.

As shown in fig. 4, the room temperature tensile property of the formed part obtained in patent embodiment 1 of the present invention is shown, and the forming and the heat treatment of the sample are metallurgical phases in the same furnace and the same state.

Example 2:

a laser deposition process of nickel-base alloy powder, comprising the steps of:

selecting powder prepared by a rotary electrode atomization method of a GH4099 nickel-based alloy bar, wherein the particle size distribution is 75-185 microns, the sphericity is 0.97, drying the powder at 200 ℃ for 2h, and the chemical components of the powder are as follows: 17.96% of Cr, 0.04% of C, 4.15% of Mo, 2.12% of Al, 6.49% of Co, 0.16% of Si, 0.02% of Mn, 5.88% of W, 1.28% of Ti, and the balance of Ni and inevitable impurities.

Carrying out proper grinding treatment on the stainless steel plate, and cleaning the surface by using an acetone solution after the treatment;

setting laser deposition technological parameters, wherein the scanning mode is a checkerboard, the scanning path in the checkerboard is one-way reciprocating zigzag scanning, and starting the deposition forming of a workpiece. The main technological parameters are as follows: the laser power is 2100W, the scanning speed is 850mm/min, the diameter of a light spot is 3mm, the powder feeding speed is 18g/min, the flow rate of a powder feeder is 10L/h, the powder feeding gas is argon, the deposition layering thickness is 1mm, the pass overlapping rate is 35%, and the oxygen content is controlled below 1100ppm in the forming process;

and (3) after the forming is finished, carrying out heat treatment on the workpiece by adopting a heat treatment system of 1140 +/-10 ℃, preserving heat for 1.5h, carrying out air cooling, preserving heat for 5h at 900 +/-10 ℃, and carrying out air cooling.

FIG. 5 is a metallographic structure photograph of the sample after solution aging heat treatment in this test case, the microstructure of the sample is compact, metallurgical defects such as lack of fusion in the layer and slag inclusion between layers are not seen, and precipitates at the grain boundary of the sample are obvious and the structure is uniform after solution aging treatment.

FIG. 6 shows the 700 ℃ tensile result of the sample in case 2 of the invention, and from the result, the tensile strength of the sample is not less than 800MPa, the yield strength is not less than 600MPa, and the elongation is not less than 14% at 700 ℃ after the sample is subjected to heat treatment, so that the performance index requirements of the material in the aerospace field can be met.

Example 3:

a laser deposition method of nickel-based alloy laser deposition powder comprises the following steps:

selecting powder prepared by a rotary electrode atomization method of a GH4099 nickel-based alloy bar, wherein the particle size distribution is 75-185 microns, the sphericity is 0.96, drying the powder at 200 ℃ for 2h, and the chemical components of the powder are as follows: 18.61% of Cr, 0.06% of C, 4.05% of Mo, 1.89% of Al, 6.27% of Co, 0.14% of Si, 0.02% of Mn, 5.88% of W, 1.19% of Ti, and the balance of Ni and inevitable impurities.

Carrying out proper grinding treatment on the stainless steel plate, and cleaning the surface by using an acetone solution after the treatment;

setting laser deposition technological parameters, wherein the scanning mode is a checkerboard, the scanning path in the checkerboard is one-way reciprocating zigzag scanning, and starting the deposition forming of a workpiece. The main technological parameters are as follows: the laser power is 2000W, the scanning speed is 900mm/min, the diameter of a light spot is 3.5mm, the powder feeding speed is 21g/min, the flow rate of a powder feeder is 11L/h, the powder feeding gas is argon, the deposition layering thickness is 1.5mm, the pass overlapping rate is 40%, and the oxygen content is controlled below 1100ppm in the forming process; the scanning mode is single-layer strip-shaped reciprocating scanning, and the included angle of the scanning channels of the upper layer and the lower layer is 50 degrees;

and (3) after the forming is finished, carrying out heat treatment on the workpiece by adopting a heat treatment system of 1140 +/-10 ℃, preserving heat for 1.5h, air cooling, preserving heat for 10h at 800 +/-10 ℃, and air cooling.

And finally, grinding and polishing the surface of the part subjected to laser deposition.

Fig. 7 shows the fracture morphology of the sample after being stretched at 900 ℃ in case 3 of the present invention, the fracture at room temperature of the sample shows fracture along the crystal toughness, equiaxial dimple distribution of the fracture surface is uniform, the fracture generates a large number of micro dimple holes due to plastic deformation in the micro-region range, no obvious crack source and propagation path are found, no crack nucleation and propagation due to poor compactness, slag inclusion and fusion are found, fig. 7a is 500#, and fig. 7b is 1000 #.

FIG. 8 shows the results of the 900 ℃ tensile test of the sample in case 3 of the present invention, in which the tensile strength is not less than 320MPa, the yield strength is not less than 260MPa, and the elongation is not less than 12%.

The invention limits the factors and conditions which obviously influence the laser deposition powder and the laser deposition process, and if the factors and conditions are not in the process condition range limited by the invention, the problem that the powder cannot be fed due to powder blockage can occur, so that the laser deposition cannot be continuously carried out, or the adverse phenomena of cracks, pore defects, unqualified performance of the deposition layer and the like exist between the laser deposition layer and the substrate can occur.

The invention effectively avoids the problems of poor fusion and internal quality such as low deposition efficiency, metallurgical defects, grain boundary cracking and the like in the laser deposition process, so that the tensile property of the workpiece at room temperature, 700 ℃ and 900 ℃ can meet the requirements of aerospace application indexes. Aiming at the actual needs of the current industry, the invention provides the nickel-based alloy laser deposition powder suitable for the conditions of high laser power and large scanning speed and the corresponding deposition method by improving GH4099 nickel-based alloy components and optimizing the deposition process.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.