A method for simultaneously producing single and double-sided stainless steel clad plates

Abstract

This invention relates to a method for simultaneously producing single-sided and double-sided stainless steel composite plates, comprising steps such as billet preparation, billet processing, application of release agent, spot welding assembly of composite materials, surface treatment of the composite billet, alignment of the assembly, vacuum electron beam welding, defect repair welding, heating of the composite billet, and rolling of the composite billet. This invention, through vacuum welding and heated rolling of double-layer sandwich plates, enables the simultaneous production of both single-sided and double-sided stainless steel composite plates from a single set of composite billets. The rolled stainless steel composite plates exhibit satisfactory flaw detection results, with performance far exceeding user requirements. Furthermore, it allows for mass production and industrialization, providing strong technical support for the stable production of single-sided / double-sided stainless steel composite plates.

Description

Technical Field

[0001] This invention relates to the field of metal material processing technology, and in particular to a method for simultaneously producing single-sided and double-sided stainless steel composite plates. Background Technology

[0002] Stainless steel composite plates, as a new type of material, not only have the advantages of stainless steel such as strong corrosion resistance, good wear resistance, beautiful appearance, durability and easy forming, but also have the good weldability, formability, ductility and thermal conductivity of carbon steel. At the same time, they are low in cost, highly adaptable and have a wide range of applications.

[0003] Stainless steel composite panels typically consist of a stainless steel cladding layer and a carbon steel or alloy steel base layer. The stainless steel cladding layer ensures the product's corrosion resistance, while the base layer guarantees its strength. Using stainless steel composite panels effectively reduces costs, saves precious metals such as nickel and chromium, aligns with national energy conservation and emission reduction policies, and promotes sustainable resource development.

[0004] Currently, stainless steel-carbon steel composite plates produced using explosive welding methods both domestically and internationally are mainly single-sided composites, with few reports on double-sided composites. From the perspective of explosive welding principles and processes, double-sided secondary explosive welding is the same as single-sided explosive welding. However, considering the mechanical properties and corrosion resistance of the weld interface, the interface already exhibits certain explosive welding stress during the first explosive welding process. Therefore, the second double-sided explosive welding will inevitably affect the welding quality and interface properties of the interface from the first explosive welding, and this effect has not yet been reported in research. There are no reports or literature domestically or internationally regarding the production of double-sided stainless steel composite plates using vacuum composite welding and rolling methods, and the simultaneous production of single-sided / double-sided stainless steel composite plates using vacuum composite welding and rolling methods is unprecedented. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a method for simultaneously producing single-sided and double-sided stainless steel composite plates. By placing the stainless steel within the frame, it provides adequate space for movement of the stainless steel at the start of rolling. This effectively solves the technical problem that when stainless steel is directly welded to carbon steel, there is no space for movement of the stainless steel during rolling. Furthermore, due to the difference in high-temperature ductility between stainless steel and carbon steel, some areas of the composite surface cannot be completely laminated, resulting in large areas of non-compliant flaw detection in the rolled composite billet.

[0006] The technical solution adopted in this invention is as follows:

[0007] The method for simultaneously producing single-sided and double-sided stainless steel composite panels proposed in this invention specifically includes the following steps: S1. Blank preparation: Three pieces of carbon steel base material; the upper base material is marked as A, the middle base material as B, and the lower base material as C; four pieces of stainless steel composite material, marked as D, E, F, and G respectively; two borders, marked as H and I respectively. S2, Carbon steel substrate processing; S3, border processing; S4, Stainless steel composite processing; S5. Apply release agent; wipe one side of the composite stainless steel (D and E) clean, then apply oxide release agent, let it dry in dry air, and then put it in an electric heating furnace to heat it until the oxide release agent is completely dry. S6. Combine the stainless steel composites D and E with the oxide release agent applied on the inward side and connect them by spot welding; S7. After spot welding, grind the upper and lower surfaces of the assembled stainless steel billet until all metal is visible on the surface and wipe it clean. S8, composite stainless steel F and G adopt the same treatment method as composite stainless steel D and E; S9. Place the lower base carbon steel C on the centering machine base, place the frame I on it and align it with it, put the polished auxiliary composite stainless steel F and G inside the frame, hoist the middle base B to the centering machine for billet centering, place the frame H on the middle base B and align it with it, put the polished composite stainless steel D and E inside the frame H, flip the upper base A billet, hoist it to the centering machine for billet centering. S10. The assembled blanks are sent to a vacuum electron beam system for vacuum welding. S11. After welding, use the secondary imaging of the vacuum welding system to check the quality of the weld. If there are welding defects, repair welding shall be carried out. S12. The composite billet is heated in the heating furnace according to the heating regime of stainless steel composite billet (reference heating time = 2 times that of carbon steel of the same thickness). S13. Double-sided stainless steel composite plates and single-sided stainless steel composite plates can be obtained by rolling the composite billet using a special rolling system for rolling stainless steel composite billets.

[0008] Furthermore, in step S2, the surface roughness Ra of the carbon steel substrate after processing is less than 5.5 μm, and the bonding layer is completely metallic.

[0009] Furthermore, in step S3, the frame processing dimensional deviation is ≤1 mm, the flatness is ≤0.5 mm / piece, and the inner surface of the frame must not have any burrs, pits, seams, or knife marks exceeding 0.5 mm.

[0010] Furthermore, step S4 includes: squaring the composite stainless steel before assembly, cleaning the surface with a flap wheel, ensuring that the processed composite stainless steel is free from squaring and has a smooth, defect-free surface, and is not allowed to have wedge-shaped or sickle-shaped bends, with an unevenness ≤3mm / m and a roughness Ra<5.5μm.

[0011] Furthermore, in step S5, the coating thickness of the oxide release agent is 0.4-0.6 mm. After the release agent is applied, it is placed in dry air to dry for ≥4 hours, and then placed in an electric heating furnace and heated at 400-500℃ for 25-50 minutes to ensure that the release agent is completely dry.

[0012] Furthermore, in step S6, the spot welding connection area is 50% of the entire weld and is evenly distributed.

[0013] Furthermore, in step S9, after the blanks are assembled, the gaps at the joint surfaces are ensured to be no greater than 0.5 mm.

[0014] Furthermore, in step S10, the vacuum degree is <10. -2 Pa; all four side strip welds are spot welded, with a welding current of 100-150mA and a welding speed of 8-10mm / s, followed by continuous welding with a current of 300-400mA and a welding speed of 6-8mm / s.

[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention employs an overall processing technology for spot welding of stainless steel, which doubles the processing efficiency of stainless steel and reduces the complexity of billet assembly by more than 50%.

[0016] 2. The present invention uses a high-temperature baking process in an electric heating furnace, which promotes the decomposition of crystal water and solves the problem of residual moisture in the release agent.

[0017] 3. This invention, through a double-frame assembly scheme, allows stainless steel to be encapsulated in a space with a certain gap, completely buffering the resistance to heat deformation during heating and rolling. This also increases the composite effect between carbon steel and stainless steel.

[0018] 4. The present invention uses a method of encapsulating stainless steel in a frame, which enables vacuum electron beam welding to be carried out between carbon steel, reducing welding difficulty and increasing welding strength.

[0019] 5. This invention enables the simultaneous production of double-sided and single-sided stainless steel composite plates from a single set of composite billets through vacuum welding and heated rolling of double-layer sandwich plates. The flaw detection results of the rolled stainless steel composite plates are all qualified, and their performance is far superior to the user requirements, providing strong technical support for the stable production of double-sided / single-sided stainless steel composite billets. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of a method for simultaneously producing single-sided and double-sided stainless steel composite plates proposed in this invention. Detailed Implementation

[0021] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] See appendix Figure 1 The method for simultaneously producing single-sided and double-sided stainless steel composite plates proposed in this invention specifically includes the following steps: S1. Blank preparation: Three pieces of carbon steel base material; the upper base material is marked as A, the middle base material as B, and the lower base material as C; four pieces of stainless steel composite material, marked as D, E, F, and G respectively; two borders, marked as H and I respectively. The length and width of the base carbon steel are 100-120mm greater than the length and width of the composite stainless steel. The frame is made of ordinary carbon steel with a thickness 3-6mm greater than the thickness of the two composite materials. Its external dimensions are the same as those of the base carbon steel. The internal length and width of the frame after assembly are approximately 10mm greater than the corresponding length and width of the composite stainless steel, so that stainless steel can be placed inside the frame.

[0023] S2, The substrate is made of carbon steel; the surface roughness Ra after processing is <5.5μm, and the bonding layer is completely metallic.

[0024] S3. Frame processing; the standard deviation of frame processing (length, width, thickness) is ≤1 mm, the flatness is ≤0.5 mm / sheet, and the inner surface of the frame shall not have any burrs, pits, seams, or knife marks exceeding 0.5 mm.

[0025] S4. Stainless steel composite processing: Before assembly, the stainless steel composite is squared and the surface is cleaned by grinding with a flap wheel. The processed stainless steel composite must not have any squareness and the surface must be flat and free of defects. Wedge-shaped or sickle-shaped bends are not allowed. The flatness is ≤3mm / m and the roughness Ra<5.5μm.

[0026] S5. Apply release agent; wipe the oil, dust and other contaminants off the D and E sides of the composite stainless steel, and then apply a special pure, water-insoluble, high-temperature (1300℃) stable oxide release agent to the surface. The thickness of the oxide release agent should be 0.4-0.6mm. After applying the release agent, place it in dry air to dry for ≥4 hours, and then put it in an electric heating furnace and heat it at 400-500℃ for 25-50 minutes to ensure that the release agent is completely dry.

[0027] S6. Combine the stainless steel composites D and E with the oxide release agent applied on the inward side and connect them by spot welding; the spot welding connection area is about 50% of the entire weld and is evenly distributed.

[0028] S7. After spot welding, polish the top and bottom surfaces of the assembled stainless steel composite material with a flap wheel until the surface is completely exposed to metal, and wipe it clean with a non-woven cloth soaked in alcohol.

[0029] S8, composite stainless steel F and G adopt the same treatment method as composite stainless steel D and E; S9. Place the lower base carbon steel C on the centering machine base, place the frame I on it and align it, put the polished auxiliary composite stainless steel F and G inside the frame, hoist the middle base B to the centering machine for billet centering, place the frame H on the middle base B and align it, put the polished composite stainless steel D and E inside the frame H, flip the upper base A billet, hoist it to the centering machine for billet centering; after billet assembly, ensure that the gaps on the joint surfaces are no more than 0.5mm.

[0030] S10. The assembled blanks are sent to a vacuum electron beam system for vacuum welding; wherein the vacuum level is <10. - 2 Pa; all 16 welds on the four sides are spot welded, with a welding current of 100-150mA and a welding speed of 8-10mm / s; after spot welding, continuous welding is carried out, with a welding current of 350-400mA and a welding speed of 6-8mm / s.

[0031] S11. After welding, use the secondary imaging of the vacuum welding system to check the quality of the weld. If there are welding defects, repair welding shall be carried out. S12. The composite billet is heated in the heating furnace according to the heating regime of stainless steel composite billet. S13. The composite billet is rolled using a special rolling process for stainless steel to achieve the required thickness. The edges are then cut off to obtain a double-sided stainless steel composite plate (stainless steel + carbon steel + stainless steel) and a single-sided stainless steel composite plate (stainless steel + carbon steel).

[0032] The present invention will be further illustrated below through specific embodiments: This embodiment simultaneously produces AG728+304 single-sided stainless steel composite plates and 304+AG728+304 double-sided stainless steel composite plates; the finished product thickness is: 2mm+10mm for single-sided stainless steel composite blanks and 2mm+20mm+2mm for double-sided stainless steel composite blanks. The specific implementation plan is as follows: S1. Blank Preparation: Four pieces of 304 stainless steel, each measuring 20×1800×3000mm; three base materials SA-533: the upper and lower base materials, after processing, measure 110×1910×3110mm, and the middle base blank, after processing, measures 220×1910×3110mm. Two frame pieces (identical in size), 45mm thick, with an outer length and width of 1910×3110mm and an inner length and width of 1810×3010mm.

[0033] S2. Substrate processing: Surface roughness Ra < 5.5 μm, and the bonding layer is completely metallic.

[0034] S3, border processing.

[0035] S4. Stainless steel composite processing: Before assembly, the stainless steel composite is squared and the surface is cleaned by polishing with flap wheels. The processed stainless steel composite must not be squared and the surface must be flat and free of defects. Wedge-shaped or sickle-shaped bends are not allowed. The flatness is ≤3mm / m and the roughness Ra<5.5μm.

[0036] S5. Apply release agent; Divide the stainless steel composite into two groups, and first wipe the oil, dust and other contaminants off one side of each stainless steel. Then apply a special pure, water-insoluble, high-temperature (1300℃) stable oxide release agent to the surface. The release agent thickness is 0.5mm. After applying the release agent, place it in dry air to dry for ≥4 hours, and then put it in an electric heating furnace and heat it at 450℃ for 30 minutes to ensure that the release agent is completely dry.

[0037] S6. Combine the stainless steel composites with the release agent applied on the inside and spot weld them together (the spot welding area is approximately 50% of the entire weld and is evenly distributed).

[0038] S7. After spot welding, polish the top and bottom surfaces of the two assembled stainless steel composites with a flap wheel until the metal is fully visible, and wipe them clean with a non-woven cloth dampened with alcohol.

[0039] S8. Assembly: Place the lower base material on the centering machine base, place a frame on it and align it, put a set of polished composite stainless steel inside the frame, hoist the middle base plate to the centering machine for assembly and centering, place another frame on the middle base blank and align it, put another set of polished composite stainless steel inside the frame, flip the upper base blank, hoist it to the centering machine for assembly and centering, and ensure that the gaps on the joint surfaces are no more than 0.5mm after assembly.

[0040] S9. Welding; The assembled blanks are sent to a vacuum electron beam system for vacuum welding, with a vacuum level <10. -2Pa, all 16 welds on the four sides are spot welded with a welding current of 120mA and a welding speed of 8mm / s. Then, continuous welding is performed with a welding current of 350mA and a welding speed of 6mm / s.

[0041] S10. After welding, use the secondary imaging of the vacuum welding system to check the quality of the weld. If there are welding defects, repair welding shall be carried out. S11. After welding, the stainless steel composite billet is sprayed and packaged, and then placed in a heating furnace to heat the composite billet according to the heating regime of the stainless steel composite billet. S12. The composite billet is rolled using a rolling process similar to that used for rolling stainless steel, with a rolling ratio of 10. After rolling, the frame is cut off to obtain two single-sided stainless steel composite plates and one double-sided stainless steel composite plate. The dimensions of the single-sided stainless steel composite billet are (10+2)×2500×21600mm; the dimensions of the double-sided stainless steel composite plate are (2+10+2)×2500×21600mm.

[0042] By implementing the process of this invention, it is possible to produce both stable double-sided stainless steel composite plates and single-sided stainless steel composite plates using a single composite blank.

[0043] All matters not covered in this invention are common knowledge.

[0044] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for simultaneously producing single-sided and double-sided stainless steel composite panels, characterized in that, The method includes the following steps: S1. Blank preparation: Three pieces of carbon steel base material; the upper base material is marked as A, the middle base material as B, and the lower base material as C; four pieces of stainless steel composite material, marked as D, E, F, and G respectively; two borders, marked as H and I respectively. S2, Carbon steel substrate processing; S3, border processing; S4, Stainless steel composite processing; S5. Apply release agent; wipe one side of the composite stainless steel (D and E) clean, then apply oxide release agent, let it dry in dry air, and then put it in an electric heating furnace to heat it until the oxide release agent is completely dry. S6. Combine the stainless steel composites D and E with the oxide release agent applied on the inward side and connect them by spot welding; S7. After spot welding, grind the upper and lower surfaces of the assembled stainless steel billet until all metal is visible on the surface and wipe it clean. S8, composite stainless steel F and G adopt the same treatment method as composite stainless steel D and E; S9. Place the lower base carbon steel C on the centering machine base, place the frame I on it and align it with it, put the polished auxiliary composite stainless steel F and G inside the frame, hoist the middle base B to the centering machine for billet centering, place the frame H on the middle base B and align it with it, put the polished composite stainless steel D and E inside the frame H, flip the upper base A billet, hoist it to the centering machine for billet centering. S10. The assembled blanks are sent to a vacuum electron beam system for vacuum welding. S11. After welding, the quality of the weld is checked by secondary imaging of the vacuum welding system. If there are welding defects, repair welding is performed. S12. The composite billet is heated in the heating furnace according to the heating regime of stainless steel composite billet; S13. Double-sided stainless steel composite plates and single-sided stainless steel composite plates can be obtained by rolling the composite billet using a special rolling system for rolling stainless steel composite billets.

2. The method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S2, the surface roughness Ra of the carbon steel substrate after processing is less than 5.5 μm, and the bonding layer is completely metallic.

3. The method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S3, the frame processing dimensional deviation is ≤1 mm, the flatness is ≤0.5 mm / piece, and the inner surface of the frame must not have any burrs, pits, seams, or knife marks exceeding 0.5 mm.

4. The method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: Step S4 includes: squaring the composite stainless steel before assembly, cleaning the surface with a flap wheel, ensuring that the processed composite stainless steel is free of squaring and has a smooth and defect-free surface, and is not allowed to have wedge-shaped or sickle-shaped bends, with an unevenness ≤3mm / m and a roughness Ra<5.5μm.

5. A method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S5, the oxide release agent is coated with a thickness of 0.4-0.6 mm. After the release agent is coated, it is placed in dry air to dry for ≥4 hours, and then placed in an electric heating furnace and heated at 400-500℃ for 25-50 minutes to ensure that the release agent is completely dry.

6. The method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S6, the spot welding connection area is 50% of the entire weld and is evenly distributed.

7. A method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S9, after the blanks are assembled, the gaps at the joint surfaces are ensured to be no greater than 0.5 mm.

8. A method for simultaneously producing single-sided and double-sided stainless steel composite plates according to claim 1, characterized in that: In step S10, the vacuum degree is <10. -2 Pa; all four side strip welds are spot welded, with a welding current of 100-150mA and a welding speed of 8-10mm / s, followed by continuous welding with a current of 300-400mA and a welding speed of 6-8mm / s.

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