A method for manufacturing a sheet metal guide rail groove part

Abstract

The present application relates to the technical field of forming and heat treatment, and particularly relates to a preparation method of sheet metal guide rail groove parts, steps of which comprise the following: S1, first stamping forming of 0Cr17Ni7Al stainless steel plate; S2, solid solution treatment of the part after the first stamping forming; S3, profile correction of the part after the solid solution treatment; S4, second stamping forming of the corrected part; S5, austenite adjustment treatment and ice cooling treatment of the part after the second stamping forming; S6, aging treatment of the part in a profile correction die, and synchronous completion of profile correction. The method provided by the present application is suitable for profile and hardness control method of 0Cr17Ni7Al stainless steel slender sheet metal guide rail groove parts, and through optimization of forming and heat treatment process, the hardness of the part is ensured to be HRA>=70.5, and meanwhile, deformation is significantly reduced, and assembly requirements are met.

Description

Technical Field

[0001] This invention relates to the fields of forming and heat treatment technology, and in particular to a method for preparing sheet metal guide rail groove parts. Background Technology

[0002] Combination Figure 1 The diagram shows a three-dimensional structural schematic of a sheet metal guide rail groove part, which is made of 0Cr17Ni7Al. 0Cr17Ni7Al is a phase transformation precipitation hardening stainless steel, possessing excellent mechanical properties and corrosion resistance.

[0003] However, in existing technologies, insufficient control over material properties and heat treatment processes leads to parts failing to meet hardness standards (HRA < 70.5) or exhibiting soft spots. Furthermore, these parts are prone to severe torsional deformation after heat treatment, especially slender sheet metal parts with a length of 618.5 mm and a thickness of t = 1 mm, where deformation can reach 10 mm. Deformation correction is extremely difficult and severely impacts assembly quality. Therefore, a process method that can meet performance requirements while ensuring surface accuracy is urgently needed. Summary of the Invention

[0004] The main objective of this invention is to propose a method for manufacturing sheet metal guide rail groove parts, applicable to the control of the profile and hardness of slender sheet metal guide rail groove parts made of 0Cr17Ni7Al stainless steel. By optimizing the forming and heat treatment processes, the hardness of the parts is ensured to be HRA≥70.5, while significantly reducing deformation and meeting assembly requirements.

[0005] To achieve the above objectives, on the one hand, the present invention proposes a method for manufacturing sheet metal guide rail groove parts, the steps of which include:

[0006] S1. The 0Cr17Ni7Al stainless steel sheet is first stamped and formed.

[0007] S2. Solution treatment is performed on the parts after the first stamping.

[0008] S3. Perform surface correction on the parts after solution treatment;

[0009] S4. Perform a second stamping process on the corrected parts;

[0010] S5. After the second stamping, the parts are subjected to austenite adjustment treatment and refrigeration treatment in sequence.

[0011] S6. Load the parts into the calibration mold for aging treatment and simultaneously complete the surface correction.

[0012] Preferably, in step S2, the process parameters for the solution treatment are: holding at 1050±10℃ for 6 to 15 minutes, and then air-cooling to room temperature.

[0013] Preferably, in step S5, the process parameters for the austenite conditioning treatment are: holding at 955±10℃ for 8 to 20 minutes, and then rapidly air-cooling after removal from the furnace.

[0014] Preferably, in step S5, the temperature of the cryogenic treatment is -73±6℃.

[0015] Preferably, the calibration mold includes a base, a core block, and a cover plate; the base is provided with a groove for accommodating the part; the core block is used to be inserted into the part; and the cover plate is used to fasten onto the groove of the base and press the part firmly.

[0016] Preferably, the method further includes surface polishing of the parts after aging treatment to make the surface roughness Ra≤0.8.

[0017] Preferably, when performing surface polishing, metallographic sandpaper of 300# to 600# is used for polishing.

[0018] Preferably, the sheet metal guide rail groove part includes a base plate, side plates integrally formed on both sides of the base plate, and bent portions integrally formed at the top of the two side plates; during the first stamping process in step S1, the profile surface of the base plate is formed, and the two sides of the base plate are vertically bent to form the side plates; during the second stamping process in step S4, the bent portions at the top of the two side plates are formed.

[0019] Preferably, the method is applicable to slender 0Cr17Ni7Al stainless steel sheet metal guide rail groove parts with a length ≥ 500mm and a thickness of 0.5~2mm.

[0020] On the other hand, the present invention proposes a 0Cr17Ni7Al stainless steel sheet metal guide rail groove part prepared by the above method, wherein the part has a hardness HRA≥70.5 and a straightness in free state ≤1.10mm.

[0021] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0022] (1) The method provided by this invention prevents austenite stabilization and transforms as much of it as possible into martensite. Before aging, the martensite structure is essentially maintained, increasing the hardness of the part. The martensite in the microstructure is uniform, resulting in uniform part hardness and preventing soft spots. The part achieves comprehensive mechanical properties of high strength and good toughness. Furthermore, without affecting the material microstructure transformation, the aging process using a calibration mold can correct part deformation. Through two forming processes and two heat treatments, deformation accumulation is significantly reduced, and the straightness of the part is ≤0.10mm.

[0023] (2) In this invention, after the first molding, the material is heat-treated at a temperature higher than Ac3 of 0Cr17Ni7Al stainless steel for a period of time to achieve complete austenitization. Then it is rapidly cooled to significantly reduce the molding stress and soften the material to the maximum extent. Before the second molding, the material is corrected. After the second molding, the austenite adjustment treatment, ice-cold treatment and final strengthening heat treatment are performed to ensure both the surface of the part and its hardness.

[0024] (3) This invention effectively controls the surface finish and hardness of 0Cr17Ni7Al stainless steel sheet metal parts by optimizing the heat treatment and forming processes, ensuring that the quality and performance of the parts meet the requirements. The use of alternating hot and cold processing techniques, and the merging of hot processing and forming processes, simplifies the process steps, improves production efficiency, and reduces production costs. Through austenite adjustment treatment and cryogenic treatment, the martensite structure is fully transformed, effectively improving the hardness and strength of the parts, while reducing residual austenite and improving the performance stability of the parts. The simultaneous aging and forming treatments ensure that the Ni-Al strengthening phase precipitates on the martensite through aging treatment, thus strengthening the material; and that the mold ensures the surface finish accuracy of the parts.

[0025] (4) The technical solution of the present invention is applicable to the production of various 0Cr17Ni7Al stainless steel sheet metal guide rail groove parts and has a wide range of application value. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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 the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a three-dimensional structural diagram of a sheet metal guide rail groove part;

[0028] Figure 2 This is a schematic diagram of the cross-section of the part after the first stamping process;

[0029] Figure 3 This is a schematic diagram of the cross-section of the part after the second stamping process;

[0030] Figure 4 This is a schematic diagram of the calibration mold.

[0031] Figure 5 The metallographic structure of retained austenite in Embodiment 1 of the present invention;

[0032] Figure 6This refers to the martensite group formed by austenite adjustment treatment and cryogenic treatment in Embodiment 1 of the present invention.

[0033] The following are the reference numerals: 1. Base; 2. Core block; 3. Cover plate; 100. Bottom plate; 101. Side plate; 102. Bending section. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0036] Example 1:

[0037] Taking the fabrication of sheet metal guide rail groove parts using 1mm thick 0Cr17Ni7Al stainless steel sheet as an example, the sheet metal guide rail groove parts include a base plate 100, with side plates 101 integrally formed on both sides of the base plate 100, and bent portions 102 integrally formed at the top of the two side plates 101. The specific implementation process is as follows:

[0038] 1. 0Cr17Ni7Al stainless steel plates are supplied in a solution-treated and heat-treated state to ensure that the initial properties of the material meet the requirements of subsequent processing.

[0039] 2. Perform the first stamping process. According to the design requirements of the part, perform a precise stamping operation. During the first stamping process, the upper surface of the base plate 100 is formed, and at the same time, the two sides of the base plate 100 are vertically bent to form the side plates 101.

[0040] 3. Solution treatment: The parts after the first molding are subjected to solution treatment at a temperature controlled at 1050±10℃ for 6–15 minutes. The purpose of solution treatment is to eliminate molding stress, soften the parts to the maximum extent, and obtain an unstable austenitic structure, providing good material properties for subsequent processing.

[0041] 4. Correcting heat treatment deformation: Correcting the parts after solution treatment to reduce deformation caused during heat treatment and ensure the surface accuracy of the parts.

[0042] 5. Second stamping: According to the design requirements of the part, the corrected part is stamped a second time to further optimize the surface accuracy of the part. During the second stamping, the bent portions 102 at the top of the two side plates 101 are formed.

[0043] 6. Austenite Adjustment Treatment: The parts after the second forming process undergo austenite adjustment treatment at a temperature controlled at 955±10℃ for 8–20 minutes. The purpose of austenite adjustment treatment is to improve the hardness and strength of the parts by adjusting the microstructure of austenite, increasing the degree of martensite transformation, and reducing retained austenite.

[0044] 7. Cryogenic Treatment: Parts that have undergone austenite conditioning are subjected to cryogenic treatment at a temperature controlled at -73±6℃. The purpose of cryogenic treatment is to further reduce residual austenite and transform more austenite into martensite, thereby improving the hardness and strength of the parts.

[0045] 8. Aging and Shaping Process: The parts after cryogenic treatment undergo aging treatment, and a shaping mold is used for shaping to ensure the surface accuracy of the parts. The purpose of aging treatment is to further enhance the performance of the parts through phase transformation during the aging process, while the use of the shaping mold ensures the surface accuracy of the parts. The shaping mold includes a base 1, a core block 2, and a cover plate 3; the base 1 is provided with a groove for accommodating the parts; the core block 2 is used to insert into the parts; the cover plate 3 is used to fasten to the groove of the base 1 and press the parts firmly.

[0046] 9. Polishing: Use metallographic sandpaper of 300# to 600# to polish the surface of the parts to remove the oxide color on the surface of the parts until the metallic luster is exposed, and ensure that the surface roughness of the parts reaches Ra≤0.8.

[0047] 10. Inspection: Conduct a comprehensive inspection of the polished parts, including hardness testing and surface accuracy testing. Hardness testing requires the parts to have a hardness of HRA ≥ 70.5, and surface accuracy testing requires the parts to have a straightness of ≤ 1.10 mm.

[0048] Example 2:

[0049] Taking the fabrication of sheet metal guide rail groove parts using 1.5mm thick 0Cr17Ni7Al stainless steel sheet as an example, the sheet metal guide rail groove parts include a base plate 100, with side plates 101 integrally formed on both sides of the base plate 100, and bent portions 102 integrally formed at the top of the two side plates 101. The specific implementation process is as follows:

[0050] 1. 0Cr17Ni7Al stainless steel plates are supplied in a solution-treated and heat-treated state to ensure that the initial properties of the material meet the requirements of subsequent processing.

[0051] 2. Perform the first stamping process. According to the design requirements of the part, perform a precise stamping operation. During the first stamping process, the upper surface of the base plate 100 is formed, and at the same time, the two sides of the base plate 100 are vertically bent to form the side plates 101.

[0052] 3. Solution treatment: The parts after the first molding are subjected to solution treatment at a temperature controlled at 1050±10℃ for 6–15 minutes. The purpose of solution treatment is to eliminate molding stress, soften the parts to the maximum extent, and obtain an unstable austenitic structure, providing good material properties for subsequent processing.

[0053] 4. Correcting heat treatment deformation: Correcting the parts after solution treatment to reduce deformation caused during heat treatment and ensure the surface accuracy of the parts.

[0054] 5. Second stamping: According to the design requirements of the part, the corrected part is stamped a second time to further optimize the surface accuracy of the part. During the second stamping, the bent portions 102 at the top of the two side plates 101 are formed.

[0055] 6. Austenite Adjustment Treatment: The parts after the second forming process undergo austenite adjustment treatment at a temperature controlled at 955±10℃ for 8–20 minutes. The purpose of austenite adjustment treatment is to improve the hardness and strength of the parts by adjusting the microstructure of austenite, increasing the degree of martensite transformation, and reducing retained austenite.

[0056] 7. Cryogenic Treatment: Parts that have undergone austenite conditioning are subjected to cryogenic treatment at a temperature controlled at -73±6℃. The purpose of cryogenic treatment is to further reduce residual austenite and transform more austenite into martensite, thereby improving the hardness and strength of the parts.

[0057] 8. Aging and Shaping Process: The parts after cryogenic treatment undergo aging treatment, and a shaping mold is used for shaping to ensure the surface accuracy of the parts. The purpose of aging treatment is to further enhance the performance of the parts through phase transformation during the aging process, while the use of the shaping mold ensures the surface accuracy of the parts. The shaping mold includes a base 1, a core block 2, and a cover plate 3; the base 1 is provided with a groove for accommodating the parts; the core block 2 is used to insert into the parts; the cover plate 3 is used to fasten to the groove of the base 1 and press the parts firmly.

[0058] 9. Polishing: Use metallographic sandpaper of 300# to 600# to polish the surface of the parts to remove the oxide color on the surface of the parts until the metallic luster is exposed, and ensure that the surface roughness of the parts reaches Ra≤0.8.

[0059] 10. Inspection: Conduct a comprehensive inspection of the polished parts, including hardness testing and surface accuracy testing. Hardness testing requires the parts to have a hardness of HRA ≥ 70.5, and surface accuracy testing requires the parts to have a straightness of ≤ 1.10 mm.

[0060] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing a sheet metal guide rail groove part, characterized in that, The sheet metal guide rail groove part includes a base plate (100), side plates (101) integrally formed on both sides of the base plate (100), and a bent portion (102) integrally formed at the top of the two side plates (101). The manufacturing method includes: S1. The 0Cr17Ni7Al stainless steel sheet is first stamped and formed. S2. Solution treatment is performed on the parts after the first stamping. S3. Perform surface correction on the parts after solution treatment; S4. Perform a second stamping process on the corrected parts; S5. After the second stamping, the parts are subjected to austenite adjustment treatment and refrigeration treatment in sequence. S6. Load the parts into the calibration mold for aging treatment and simultaneously complete the surface correction. During the first stamping process in step S1, the upper surface of the base plate (100) is formed, and the two sides of the base plate (100) are vertically bent to form the side plate (101). During the second stamping process in step S4, the bent portions (102) at the top of the two side plates (101) are formed. In step S5, the process parameters for the austenite conditioning treatment are: holding at 955±10℃ for 8 to 20 minutes, and then rapidly air-cooling after removal from the furnace.

2. The method as described in claim 1, characterized in that, In step S2, the process parameters for the solution treatment are: heat treatment at 1050±10℃ for 6 to 15 minutes, followed by air cooling to room temperature.

3. The method as described in claim 1, characterized in that, In step S5, the temperature of the cryogenic treatment is -73±6℃.

4. The method as described in claim 1, characterized in that, The calibration mold includes a base (1), a core block (2), and a cover plate (3); A groove for accommodating parts is provided on the base (1); The core block (2) is used to be inserted into the part; The cover plate (3) is used to fasten onto the groove of the base (1) and press the parts.

5. The method as described in claim 1, characterized in that, The method also includes surface polishing of the parts after aging treatment to make the surface roughness Ra≤0.

8.

6. The method as described in claim 5, characterized in that, When performing surface polishing, use metallographic sandpaper with a grit size of 300# to 600#.

7. The method as described in claim 1, characterized in that, The method is applicable to slender 0Cr17Ni7Al stainless steel sheet metal guide rail groove parts with a length ≥ 500mm and a thickness of 0.5~2mm.

8. A 0Cr17Ni7Al stainless steel sheet metal guide rail groove part prepared by the method according to any one of claims 1-7, characterized in that, The part has a hardness HRA≥70.5 and a straightness in its free state ≤1.10mm.

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