A method for welding thin-walled heat-resistant stainless steel parts

Abstract

The application discloses a kind of thin-walled heat-resistant stainless steel part welding methods, comprising: the welding position of two thin-walled heat-resistant stainless steel parts to be welded is washed;Machining weld groove at the welding position, and the groove is U-shaped groove;Part is preheated, preheating temperature 200 DEG C±30 DEG C, preheating time is 0.5h or more;Argon arc welding fusion welding is carried out at the groove without welding material, and the fusion welding depth is 1±0.5mm;Carrying out argon arc welding surfacing with welding material, and the welding material is HOCr21Ni10, and the weld depth is 2±0.5mm;Low-temperature tempering treatment is carried out to the part after welding, and the tempering temperature is 300 DEG C±30 DEG C, and the holding time is 1.5h.The application can improve the welding quality of thin-walled heat-resistant stainless steel part, and meet the nondestructive testing requirements.

Description

Technical Field

[0001] This invention relates to the field of welding aerospace product parts, and specifically to a welding method for thin-walled heat-resistant stainless steel parts. Background Technology

[0002] 13Cr11Ni2W2MoV is a heat-resistant stainless steel, a 12% chromium-type martensitic heat-stabilized stainless steel with high strength, moderate corrosion resistance, and a high yield strength ratio. Due to the addition of carbide-forming elements W, Mo, and V, the steel exhibits excellent comprehensive mechanical properties and thermal stability after quenching and tempering. This steel has good processability, plasticity, and weldability, making it suitable for manufacturing complex welded structural components, and is widely used in aerospace parts.

[0003] Aerospace components using 13Cr11Ni2W2MoV have irregular shapes, small dimensions, and thin walls, requiring high welding quality. Argon arc welding (ATW) is generally employed. Theoretically, H1Cr11Ni2W2MoV welding wire should be used for welding 13Cr11Ni2W2MoV. Currently, only H1Cr11Ni2W2MoV flux-cored welding wire is available in the domestic market, primarily used for MIG / MAG welding. When using H1Cr11Ni2W2MoV flux-cored welding wire for ATW, the welding current is relatively low, the weld pool volume is small, and the weld pool duration is short. The slag generated by the flux-cored wire cannot rise to the surface in time, leading to slag inclusions during weld cooling and solidification. Consequently, non-destructive testing of the internal weld quality fails to meet requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a welding method for thin-walled heat-resistant stainless steel parts, which can improve the welding quality of thin-walled heat-resistant stainless steel parts and meet the requirements of non-destructive testing.

[0005] One aspect of the present invention provides a welding method for thin-walled heat-resistant stainless steel parts, comprising:

[0006] Step S1: Clean the welding area of ​​the two thin-walled heat-resistant stainless steel parts to be welded;

[0007] Step S2: Machining a weld bevel at the welding position, the bevel being a U-shaped bevel;

[0008] Step S3: Preheat the parts at a temperature of 200℃±30℃ for a time of 0.5h or more.

[0009] Step S4: Perform argon arc welding without welding materials at the bevel, with a weld depth of 1±0.5mm;

[0010] Step S5: Perform argon arc welding with welding material H0Cr21Ni10, and the weld depth is 2±0.5mm;

[0011] Step S6: Perform low-temperature tempering on the welded parts at a temperature of 300℃±30℃ for 1.5 hours.

[0012] Preferably, in step S1, acetone is used for cleaning and drying.

[0013] Preferably, in steps S4 and S5, argon gas with a purity of 99.9% or higher is used for argon arc welding.

[0014] Preferably, the heat-resistant stainless steel is 13Cr11Ni2W2MoV.

[0015] Preferably, in step S5, the welding process parameters are: welding material diameter Welding current 70-100A, arc voltage 10V, gas flow rate 8-12L / min, tungsten electrode diameter Nozzle diameter The tungsten electrode extends 4–6 mm.

[0016] Preferably, the method further includes: step S7: performing non-destructive testing on the weld, wherein the non-destructive testing includes weld radiographic testing and surface penetrant testing.

[0017] The welding method for thin-walled heat-resistant stainless steel parts according to the above-described aspects of the present invention can improve the welding quality of thin-walled heat-resistant stainless steel parts and meet the requirements of non-destructive testing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0019] Figure 1 This is a flowchart of a welding method for thin-walled heat-resistant stainless steel parts according to one embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of a welding method for thin-walled heat-resistant stainless steel parts according to one embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] The present invention provides a welding method for thin-walled heat-resistant stainless steel parts. Figure 1 This is a flowchart of a welding method for thin-walled heat-resistant stainless steel parts according to one embodiment of the present invention. Figure 1 As shown, the welding method for thin-walled heat-resistant stainless steel parts according to the embodiments of the present invention includes steps S1 to S6. Figure 2 This is a schematic diagram illustrating a welding method for thin-walled heat-resistant stainless steel parts according to one embodiment of the present invention. Figure 2 In this embodiment, the method of the present invention is used to weld the second part 2 to both sides of the first part 1. Both the first part 1 and the second part 2 are thin-walled heat-resistant stainless steel parts, such as 13Cr11Ni2W2MoV.

[0023] In step S1, the welding positions of the two thin-walled heat-resistant stainless steel parts to be welded are cleaned to remove oil, impurities, etc. Acetone is preferably used for cleaning in this step, followed by air drying. Other cleaning solutions can also be used, but rapid drying is required. In one embodiment, since the parts using 13Cr11Ni2W2MoV are relatively small, the entire part can be cleaned in this step. The welding position is the location where the weld seam will be formed during the subsequent welding operation.

[0024] In step S2, a weld bevel 3 is machined at the welding position, such as... Figure 2 As shown, bevel 3 is a U-shaped bevel. Using a U-shaped bevel can ensure the penetration depth while reducing the weld width.

[0025] In step S3, the parts are preheated at a temperature of 200℃±30℃ for at least 0.5 hours. The preheating process can be carried out in a heat treatment furnace.

[0026] In step S4, argon arc welding without welding materials is performed at the bevel. This step is the first welding pass, using argon arc welding without welding materials to form... Figure 2 The first weld 4 in the process is protected by argon gas on the back side, with a fusion depth of 1±0.5mm to ensure that the root is fully penetrated without gaps and that the root quality meets the requirements during non-destructive testing.

[0027] In step S5, argon arc welding with added welding materials is performed. This step is the second welding pass, using argon arc welding with added welding materials to form... Figure 2 The second weld 5 in the process is made of HOCr21Ni10 welding material and has a weld depth of 2±0.5mm.

[0028] HOCr21Ni10 welding wire is a solid core welding wire used in this invention for argon arc welding of heat-resistant stainless steel parts. Its characteristics include slag-free welding, smooth welding, shallow penetration, no spatter, smooth and flat weld bead, and argon gas protection on the back side, enabling single-sided welding with double-sided forming. Its welding process parameters are shown in Table 1 below:

[0029] Table 1: Welding process parameters

[0030]

[0031] Since the welding method of this invention is used to weld thin-walled heat-resistant stainless steel parts, only the above two welding steps are required, which can meet the welding quality requirements, save welding steps, and improve production efficiency.

[0032] In one embodiment, in steps S4 and S5, the shielding argon gas used for welding must reach a certain purity value, with the argon gas purity reaching 99.99% or higher.

[0033] In step S6, the welded parts undergo low-temperature tempering at a temperature of 300℃±30℃ for 1.5 hours. If a heat treatment furnace is used for preheating in step S3, the parts can be cooled in the furnace after the low-temperature tempering.

[0034] In one embodiment, the welding method of this invention further includes step S7: performing non-destructive testing on the weld, wherein the non-destructive testing includes radiographic testing and surface penetrant testing. Radiographic testing of the weld is required to meet the requirements of YS0621-97, with a radiographic testing rate of 100% and a Level II qualification; penetrant testing is required to have a 100% radiographic testing rate and a Level I qualification.

[0035] For thin-walled heat-resistant stainless steel parts welded using the welding method of the present invention, the surface can be cleaned with acetone and packaged for storage.

[0036] The following specific examples illustrate the effects of the welding method for thin-walled heat-resistant stainless steel parts according to the embodiments of the present invention.

[0037] Example 1: For a certain aerospace cylinder part, the weld is required to meet the requirements of YS0621-97, with 100% non-destructive testing level II qualified and 100% penetrant testing level I qualified. Welding was carried out strictly according to the welding method of the present invention, and hundreds of products were manufactured and all passed non-destructive testing on the first attempt.

[0038] Example 2: A certain aerospace engine casing component required welds to meet the YS0621-97 standard, achieving 100% non-destructive testing (NDT) Level II qualification, 100% penetrant testing (PPT) Level I qualification, and passing a 10 MPa pressure resistance test. Welding was performed strictly according to the welding method described in this invention, and hundreds of products were manufactured, all passing NDT and pressure resistance tests on the first attempt.

[0039] In summary, existing technologies using H1Cr11Ni2W2MoV flux-cored welding wire for TIG welding of 13Cr11Ni2W2MoV heat-resistant stainless steel parts result in slag floating to the surface. This is suitable for high-current and deep-penetration welding, and performs well with thicker parts. However, for thin-walled parts, the slag doesn't have time to float to the surface, leading to slag inclusions in the weld and failing to meet non-destructive testing requirements. The welding method of this invention uses HOCr21Ni10 welding material instead of H1Cr11Ni2W2MoV for welding thin-walled heat-resistant stainless steel. Since HOCr21Ni10 is a solid wire, no slag floats during TIG welding, resulting in shallower weld penetration. This method is suitable for welding small, thin-walled parts, has minimal impact on weld strength, and increases weld toughness, meeting the quality requirements for non-destructive testing.

[0040] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A welding method for thin-walled heat-resistant stainless steel parts, characterized in that, include: Step S1: Clean the welding area of ​​the two thin-walled heat-resistant stainless steel parts to be welded; Step S2: Machine a weld bevel at the welding position. The bevel is a U-shaped bevel. Step S3: Preheat the parts at a temperature of 200℃±30℃ for a time of 0.5h or more. Step S4: Perform argon arc welding without welding materials at the bevel, with a weld depth of 1±0.5mm; Step S5: Perform argon arc welding with welding material H0Cr21Ni10, and the weld depth is 2±0.5mm; Step S6: Perform low-temperature tempering on the welded parts at a temperature of 300℃±30℃ for 1.5 hours. The heat-resistant stainless steel is 13Cr11Ni2W2MoV.

2. The method as described in claim 1, characterized in that, In step S1, acetone is used for cleaning and drying.

3. The method as described in claim 1 or 2, characterized in that, In steps S4 and S5, argon gas with a purity of 99.9% or higher is used for argon arc welding.

4. The method as described in claim 1 or 2, characterized in that, In step S5, the welding process parameters are: welding material diameter Ø1.6mm, welding current 70~100A, arc voltage 10V, gas flow rate 8~12L / min, tungsten electrode diameter ø2mm, nozzle diameter ø8~ø11mm, and tungsten electrode extension length 4~6mm.

5. The method as described in claim 1 or 2, characterized in that, Also includes: Step S7: Perform non-destructive testing on the weld, including radiographic testing and surface penetrant testing.

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