Laser composite-roller annealing method for high-strength steel and stainless steel composite plate

Abstract

The application discloses a laser composite-roller annealing method for high-strength steel and stainless steel composite plates, which is characterized by the following steps: strengthening the surface of the stainless steel by ultrasonic rolling, combining with the precise temperature control and softening of the surface layer of the high-strength steel by the homogenizing laser spot of the copper integrating mirror to reduce the hardness difference between the two to ≤30%, and significantly improving the deformation coordination; synchronously applying an auxiliary composite laser beam to complete rolling and composite, and integrating warm-pressing annealing and online flattening to realize the continuity of composite, annealing and flattening, reduce 3-5 processes, and realize short process; the thermal-mechanical coupling effect promotes the diffusion of interface atoms during the warm-pressing annealing process, forms a continuous solid solution structure, and further improves the interface bonding strength; the method is suitable for the composite of 500-1000 MPa high-strength steel and austenitic / dual-phase stainless steel, the parameter adjustment range is wide, and the efficient production of 1-5 mm thick plates is supported.

Description

Technical Field

[0001] The present invention relates to the technical field of metal composite plate rolling, and in particular to a laser composite-rolling annealing method for a high-strength steel and stainless steel composite plate. Background Art

[0002] Carbon steel-stainless steel clad plates combine the excellent mechanical properties of carbon steel with the corrosion resistance of stainless steel and are widely used in fields such as petrochemicals, marine engineering, and aerospace. However, with the increasing demands for material performance in modern industry, the strength of traditional carbon steel-stainless steel clad plates is no longer sufficient to meet the lightweight, high-load-bearing, and long-life requirements of high-end equipment. Therefore, high-strength steel-stainless steel clad plates have become a key development direction, requiring them to achieve higher strength while maintaining excellent corrosion resistance.

[0003] However, the existing process is not suitable for the composite of high-strength steel and stainless steel with a large difference in strength and a small difference in melting point. Specifically, on the one hand, the existing composite process is only applicable to steel and stainless steel with a small difference in strength. For example, the patent with application number 202311553020.7 proposes a method for preparing a low-alloy-stainless steel composite steel coil. By obtaining a single-sided stainless steel slab, heating, seven passes of rough rolling, finishing rolling and coiling, a low-alloy steel / stainless steel composite plate is prepared. However, the strength of the low-alloy steel on the stainless steel side of this method is relatively low. If the low-alloy steel is replaced with high-strength steel, the composite quality of the stainless steel layer of the prepared composite plate is insufficient, affecting the corrosion resistance. On the other hand, the patent with application number 202411698282.7 proposes a rolled extra-thick stainless steel composite plate and its production method. By welding and composite the billets, vacuuming, controlled rolling, and tempering heat treatment, a stainless steel composite plate with a tensile strength of >550MPa is finally obtained. However, this method requires circulation between different processes, and is not efficient.

[0004] Therefore, the present invention proposes a laser composite-roll annealing method for high-strength steel and stainless steel composite plates, which aims to solve the problems of coordinated deformation and metallurgical bonding between high-strength steel plates and stainless steel plates with large strength differences, and to achieve efficient and high-quality composite processing of high-strength steel plates and stainless steel plates with high shear strength. Summary of the Invention

[0005] In order to solve the problems of coordinated deformation and metallurgical bonding between high-strength steel and stainless steel with large strength differences in the existing rolling composite process, the present invention provides a laser composite-roll annealing method for high-strength steel and stainless steel composite plates. The method uses the coordinated treatment of stainless steel nano-strengthening and high-strength steel laser softening to reduce the hardness difference and solve the problem of coordinated deformation. The integrated laser composite-roll annealing process completes composite, annealing, and leveling online, reduces process flow, realizes short-process and efficient production, and has high interface bonding strength of the composite plate.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a laser composite-roll annealing method for a high-strength steel and stainless steel composite plate, comprising the following steps:

[0008] S1. Nano-treatment of stainless steel surface:

[0009] The surface of the stainless steel plate to be composited is strengthened by an ultrasonic rolling device, and the microhardness of the surface of the stainless steel plate to be composited after the treatment is 220 to 380 HV, and the depth of the treatment layer is 150 to 200 μm;

[0010] S2. Laser pretreatment of high-strength steel surface:

[0011] A copper integrating mirror is used to homogenize the spot energy distribution to obtain a preheating spot with a flat-top energy distribution. Combined with the temperature control of a pyrometer, the surface of the high-strength steel plate to be composited is softened and pretreated. After the treatment, the microhardness of the surface of the high-strength steel plate to be composited is reduced to 200-400 HV.

[0012] S3, Laser compound:

[0013] The stainless steel plate with surface hardening after ultrasonic rolling and the high-strength steel plate with surface softening pretreatment by laser irradiation are fed into the composite rollers, and layered composite is achieved under the action of the auxiliary composite processing laser beam to obtain a high-strength steel stainless steel composite plate;

[0014] S4, online roll annealing:

[0015] The high-strength steel and stainless steel composite plates after laser composite processing enter the roller annealing device to simultaneously achieve the improvement of the bonding strength, annealing and leveling of the composite plates.

[0016] Using the above technical solution:

[0017] An ultrasonic rolling device applies high-frequency vibration (20-40 kHz) and static pressure (200-400 N) to the surface of the stainless steel plate to be bonded, producing intense plastic deformation at the surface layer and forming a nanocrystalline structure. This significantly increases the surface hardness of the stainless steel plate to 220-380 HV, while also controlling the depth of the strengthening layer (150-200 μm). A copper integrating mirror is used to homogenize the laser energy distribution (uniformity ≥ 95%), and combined with real-time monitoring by a pyrometer, the heating temperature of the high-strength steel plate to be bonded is precisely controlled (400-700°C). This dynamic tempering effect reduces the surface microhardness (to 200-400 HV), forming a gradient softening layer, and reducing the hardness difference with the stainless steel plate to ≤30%. In traditional processes, the hardness difference between stainless steel and high-strength steel can reach over 150 HV, leading to stress concentration and cracking at the composite interface. In this invention, through the synergistic treatment of dissimilar metals, this hardness difference is reduced to ≤30%, significantly improving deformation coordination and increasing the interface bonding strength by over 20%.

[0018] Subsequently, online laser composite rolling was adopted: by adjusting the spatial angle between the high-strength steel plate and the stainless steel plate (50-80°), combined with the thermal effect of the auxiliary composite laser beam (power 1300-2500W), metal atom diffusion and metallurgical bonding were achieved during the rolling process (speed 0.5-2.8mm / s, reduction rate 33-60%), avoiding the risk of interface oxidation in traditional multi-pass rolling.

[0019] Finally, the high-strength steel and stainless steel composite plates after laser composite processing pass through the guide rollers and enter the roller annealing device to simultaneously achieve bonding strength improvement, annealing and leveling. The entire process is completed online, reducing 3 to 5 flow processes in the traditional process.

[0020] Furthermore, in step S2, when the tensile strength of the high-strength steel plate is 500-800 MPa, the width of the preheating spot is set to 2-3 mm, the maximum surface heating temperature of the preheating spot irradiation area is 400-550°C, and the microhardness of the surface of the high-strength steel plate to be composited after treatment is reduced to 200-290 HV.

[0021] Furthermore, the distance between the preheating spot in step S2 and the auxiliary composite processing laser spot in step S3 is 2 to 3 mm.

[0022] Furthermore, in step S2, when the tensile strength of the high-strength steel plate is greater than 800 MPa, the width of the preheating spot is set to 3-5 mm, the maximum surface heating temperature of the preheating spot irradiation area is 500-700°C, and the microhardness of the surface of the high-strength steel plate to be composited after treatment is reduced to 320-400 HV.

[0023] Furthermore, the distance between the preheating spot in step S2 and the auxiliary composite processing laser spot in step S3 is ≤1.5 mm.

[0024] The method of this invention is highly universal and adaptable to high-strength steels. By adjusting the laser pretreatment parameters (spot width 2-5 mm, temperature 400-700°C), it can be used for high-strength steels with tensile strengths of 500-1000 MPa (such as DP steel, martensitic steel, TRIP steel, etc.), and the microhardness control range covers 200-400 HV. It also has good compatibility with stainless steel and is suitable for austenitic stainless steels such as 304 / 316L and duplex stainless steels. The strengthening effect and strengthening depth can be flexibly adjusted. Examples have demonstrated the cladding of 1-3 mm thick stainless steel with 1.5-3 mm thick high-strength steel. By adjusting the roll spacing and reduction ratio, it can be expanded to cladding thick plates of 5 mm or more, and is applicable to both thin and thick plates.

[0025] Furthermore, in the step S1, during the treatment process of the ultrasonic rolling device, the ultrasonic rolling static pressure is 200-400N, the ultrasonic frequency is 20-40kHZ, and the ultrasonic amplitude is 5-7μm.

[0026] After multiple tests, it was verified that excessive static pressure, frequency, and amplitude of ultrasonic rolling will cause microcracks on the stainless steel surface and worsen the roughness. If the parameters are too small, the surface microhardness will not be sufficiently strengthened and the depth will not be enough. During the later composite process, the deformation cannot be well coordinated with the high-strength steel composite surface.

[0027] In specific applications, if the strengthening depth of the surface of the stainless steel plate to be composited does not reach 150 μm, the number of ultrasonic rolling devices can be increased to 2 to 5 groups.

[0028] Furthermore, in step S3, the auxiliary composite processing laser beam is based on a microlens array to achieve spot homogenization and shaping, and the spot width is consistent with the width of the composite material to be composited. The auxiliary composite processing laser beam power is 1300~2500W, the rolling composite speed is 0.5~2.8mm / s, and the reduction rate is 33~60%.

[0029] After multiple tests and verifications, it was found that laser power and rolling speed jointly affect heat input. If the heat input is too high, the steel will melt and stick to the surface of the roller, affecting the composite processing. If the heat input is insufficient, rolling composite cannot be achieved with a smaller reduction rate. If the reduction rate is too high, the composite plate will be severely deformed. If the reduction rate is too small, the interface bonding strength will be insufficient.

[0030] Furthermore, in step S4, the roller annealing device is composed of a warm pressing mechanism and a hot straightening mechanism.

[0031] Furthermore, the temperature pressing mechanism is composed of multiple groups of roller systems with a diameter of 160 to 200 mm and induction coils installed inside the rollers. The surface temperature of the rollers is 230 to 400°C, and the reduction rate of each group of rollers is 3 to 5%, so as to further improve the interface bonding strength through thermal-mechanical synergy.

[0032] The thermal activation effect (interface temperature ≥ 500°C) and mechanical pressure (3-5% reduction rate) in the warm pressing stage work synergistically to increase the interface atomic diffusion coefficient by 3-5 times, forming a continuous solid solution structure in the bonding area.

[0033] Furthermore, the hot straightening mechanism consists of an induction heating module, an air cooling device, and a leveling work roll. After the high-strength steel stainless steel composite plate passes through the temperature pressing mechanism, it is first annealed using the induction heating module. The heating temperature of the induction annealing treatment is 550-700°C, and it is carried out under an argon and nitrogen atmosphere. Then it enters the air cooling device for cooling treatment, the temperature of which is lower than 150°C, and finally enters the leveling work roll for leveling treatment to obtain a high-strength steel stainless steel composite plate with a wave height of ≤2mm / m.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) By nano-sizing the surface structure of stainless steel at the interface to be composited and softening the surface structure of high-strength steel at the interface to be composited, the microhardness difference between the metals on both sides of the interface to be composited is significantly reduced, that is, the deformation coordination of the two metals with large differences during the composite processing is improved, so as to achieve metallurgical bonding between dissimilar metals with large strength differences.

[0036] (2) Online laser composite rolling is adopted. By adjusting the spatial angle between the high-strength steel plate and the stainless steel plate and combining the thermal effect of the auxiliary composite laser beam, the diffusion of metal atoms and metallurgical bonding are achieved during the rolling process, thus avoiding the risk of interface oxidation in traditional multi-pass rolling.

[0037] (3) By utilizing the coordinated work of the temperature pressing mechanism and the hot straightening mechanism, the high-strength steel stainless steel composite plate after laser composite processing is subjected to online roller annealing treatment. On the one hand, under the action of thermal-mechanical coupling, the diffusion capacity of atoms near the bonding interface is enhanced, and the interface bonding strength of the composite plate is further improved; on the other hand, the online annealing and straightening treatment after composite processing reduces the process flow and realizes short process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Figure 1 This is a schematic diagram of the laser composite-roll annealing operation process of the high-strength steel and stainless steel composite plate of the present invention. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] Example 1

[0042] A laser composite-roll annealing method for high-strength steel and stainless steel composite plates, such as Figure 1 As shown, the following steps are included:

[0043] S1. Nano-treatment of stainless steel surface:

[0044] A 1mm thick stainless steel strip was selected, and the surface of the stainless steel to be composited was subjected to surface strengthening treatment using an ultrasonic rolling device arranged between the front tension roller and the limit roller group. The ultrasonic rolling static pressure was 200N, the ultrasonic frequency was 40kHZ, and the ultrasonic amplitude was 5μm. The microhardness of the treated stainless steel plate to be composited was 325HV, and the depth of the treated layer was 165μm.

[0045] S2. Laser pretreatment of high-strength steel surface:

[0046] High-strength steel with a thickness of 2 mm and a tensile strength of 600 MPa was selected. Based on the spot homogenization and shaping mechanism of the copper integrating mirror, a preheating spot with a flat-top energy distribution with a width of 2 mm was obtained. Combined with the coaxial coupling of the pyrometer, the maximum surface heating temperature of the laser irradiation area was controlled to 450°C. The preheating spot was used to achieve softening pretreatment of the high-strength steel surface to be bonded. The microhardness of the treated high-strength steel plate to be composited was reduced to 283 HV. The microhardness test standard is GB / T4340.1-2024.

[0047] S3, Laser compound:

[0048] Using the upper and lower limiting roller groups, the spatial angle between the high-strength steel and the stainless steel is adjusted to 70°, and the surface-hardened stainless steel plate treated by the ultrasonic rolling device and the high-strength steel plate pre-treated by laser irradiation surface softening are fed into the composite rolling roller. Under the action of the auxiliary composite processing laser beam, layered composite is achieved. The auxiliary composite processing laser beam power is 1300W, the rolling composite speed is 0.5mm / s, and the reduction rate is 40%, thereby obtaining a high-strength steel stainless steel composite plate.

[0049] S4, online roll annealing:

[0050] After laser composite processing, the high-strength steel and stainless steel composite plates enter the roller annealing device. The roller annealing device consists of a warm pressing mechanism and a hot straightening mechanism. The warm pressing mechanism consists of three sets of rollers with a diameter of 180mm and induction coils installed inside the rollers. The surface temperature of the rollers is 350℃, and the reduction rate of each set of rollers is 3% to further improve the interfacial bonding strength through thermal-mechanical synergy. The hot straightening mechanism consists of an induction heating module, an air cooling device, and a leveling work roll. After the high-strength steel and stainless steel composite plates pass through the warm pressing mechanism, they are first annealed using the induction heating module. The induction annealing treatment is carried out at a heating temperature of 600℃ and is carried out in an argon and nitrogen atmosphere. Then they enter the air cooling device for cooling treatment, the temperature of which is below 150℃, and finally enter the leveling work roll for leveling treatment, obtaining a high-strength steel and stainless steel composite plate with an unevenness of 1.6mm / m.

[0051] The high-strength steel stainless steel composite plate prepared in this embodiment has a thickness of 1.64 mm and an interface shear strength of 192 MPa. The shear strength test standard is GB / T 6396-2008.

[0052] Example 2

[0053] A laser composite-roll annealing method for a high-strength steel and stainless steel composite plate comprises the following steps:

[0054] S1. Nano-treatment of stainless steel surface:

[0055] A 1mm thick stainless steel strip was selected, and the surface of the stainless steel to be composited was subjected to surface strengthening treatment using an ultrasonic rolling device arranged between the front tension roller and the limit roller group. The ultrasonic rolling static pressure was 300N, the ultrasonic frequency was 20kHZ, and the ultrasonic amplitude was 5μm. The microhardness of the treated stainless steel plate to be composited was 330HV, and the depth of the treated layer was 160μm.

[0056] S2. Laser pretreatment of high-strength steel surface:

[0057] High-strength steel with a thickness of 1.5 mm and a tensile strength of 800 MPa was selected. Based on the spot homogenization and shaping mechanism of the copper integrator mirror, a preheating spot with a flat-top energy distribution with a width of 3 mm was obtained. Combined with the coaxial coupling of the pyrometer, the maximum surface heating temperature of the laser irradiation area was controlled to 550°C. The preheating spot was used to achieve softening pretreatment of the high-strength steel surface to be bonded. The microhardness of the treated high-strength steel plate to be composited was reduced to 291 HV.

[0058] S3, Laser compound:

[0059] Using the upper and lower limiting roller groups, the spatial angle between the high-strength steel and the stainless steel is adjusted to 70°, and the surface-hardened stainless steel plate treated by the ultrasonic rolling device and the high-strength steel plate pre-treated by laser irradiation surface softening are fed into the composite rolling roller. Under the action of the auxiliary composite processing laser beam, layered composite is achieved. The auxiliary composite processing laser beam power is 2000W, the rolling composite speed is 1.5mm / s, and the reduction rate is 33%, thereby obtaining a high-strength steel stainless steel composite plate.

[0060] S4, online roll annealing:

[0061] After laser composite processing, the high-strength steel and stainless steel composite plates enter the roller annealing device, which consists of a warm pressing mechanism and a hot straightening mechanism. The warm pressing mechanism consists of three sets of rollers with a diameter of 180mm and induction coils installed inside the rollers. The surface temperature of the rollers is 400℃, and the reduction rate of each set of rollers is 3% to further improve the interfacial bonding strength through thermal-mechanical synergy. The hot straightening mechanism consists of an induction heating module, an air cooling device, and a leveling work roll. After the high-strength steel and stainless steel composite plates pass through the warm pressing mechanism, they are first annealed using the induction heating module. The induction annealing treatment is carried out at a heating temperature of 600℃ and is carried out in an argon and nitrogen atmosphere. They then enter the air cooling device for cooling treatment, whose temperature is below 150℃. Finally, they enter the leveling work roll for leveling treatment, obtaining a high-strength steel and stainless steel composite plate with an unevenness of 1.5mm / m.

[0062] The high-strength steel stainless steel composite plate prepared in this embodiment has a thickness of 1.51 mm and an interface shear strength of 197 MPa.

[0063] Example 3

[0064] A laser composite-roll annealing method for a high-strength steel and stainless steel composite plate comprises the following steps:

[0065] S1. Nano-treatment of stainless steel surface:

[0066] A 2mm thick stainless steel strip was selected, and the surface of the stainless steel to be composited was subjected to surface strengthening treatment using an ultrasonic rolling device arranged between the front tension roller and the limit roller group. The ultrasonic rolling static pressure was 400N, the ultrasonic frequency was 20kHZ, and the ultrasonic amplitude was 7μm. The microhardness of the treated stainless steel plate to be composited was 332HV, and the depth of the treated layer was 180μm.

[0067] S2. Laser pretreatment of high-strength steel surface:

[0068] High-strength steel with a thickness of 3 mm and a tensile strength of 1000 MPa was selected. Based on the spot homogenization and shaping mechanism of the copper integrator mirror, a preheating spot with a flat-top energy distribution with a width of 5 mm was obtained. Combined with the coaxial coupling of the pyrometer, the maximum surface heating temperature of the laser irradiation area was controlled to 700°C. The preheating spot was used to achieve softening pretreatment of the high-strength steel surface to be bonded. The microhardness of the treated high-strength steel plate to be composited was reduced to 323 HV.

[0069] S3, Laser compound:

[0070] Using the upper and lower limiting roller groups, the spatial angle between the high-strength steel and the stainless steel is adjusted to 70°, and the surface-hardened stainless steel plate treated by the ultrasonic rolling device and the high-strength steel plate pre-treated by laser irradiation surface softening are fed into the composite rolling roller. Under the action of the auxiliary composite processing laser beam, layered composite is achieved. The auxiliary composite processing laser beam power is 2500W, the rolling composite speed is 2.8mm / s, and the reduction rate is 60%, thereby obtaining a high-strength steel stainless steel composite plate.

[0071] S4, online roll annealing:

[0072] After laser composite processing, the high-strength steel and stainless steel composite plates enter the roller annealing device. The roller annealing device consists of a warm pressing mechanism and a hot straightening mechanism. The warm pressing mechanism consists of three sets of rollers with a diameter of 180mm and induction coils installed inside the rollers. The surface temperature of the rollers is 400℃, and the reduction rate of each set of rollers is 5% to further improve the interfacial bonding strength through thermal-mechanical synergy. The hot straightening mechanism consists of an induction heating module, an air cooling device, and a leveling work roll. After the high-strength steel and stainless steel composite plates pass through the warm pressing mechanism, they are first annealed using the induction heating module. The induction annealing treatment is carried out at a heating temperature of 600℃ and is carried out in an argon and nitrogen atmosphere. Then they enter the air cooling device for cooling treatment, the temperature of which is below 150℃, and finally enter the leveling work roll for leveling treatment, obtaining a high-strength steel and stainless steel composite plate with an unevenness of 1.8mm / m.

[0073] The high-strength steel stainless steel composite plate prepared in this embodiment has a thickness of 1.72 mm and an interface shear strength of 208 MPa.

[0074] Comparative Example 1

[0075] Comparative Example 1 is a comparative test example of Example 1, in which the stainless steel surface is not subjected to nano-processing, and other implementation steps and specific parameters are the same as those of Example 1.

[0076] The high-strength steel-stainless steel composite plate prepared in this comparative example has a thickness of 1.64 mm and an interface shear strength of 103 MPa.

[0077] Comparative Example 2

[0078] Comparative Example 2 is a comparative test example of Example 1, in which the high-strength steel surface is not subjected to laser softening pretreatment, and other implementation steps and specific parameters are the same as those of Example 1.

[0079] The high-strength steel stainless steel composite plate prepared in this comparative example has a thickness of 1.66 mm and an interface shear strength of 121 MPa.

[0080] Comparative Example 3

[0081] Comparative Example 3 is a comparative test example of Example 1, in which the stainless steel surface is not subjected to nano-processing, and the high-strength steel surface is not subjected to laser softening pretreatment. Other implementation steps and specific parameters are the same as those of Example 1.

[0082] The high-strength steel-stainless steel composite plate prepared in this comparative example has poor bonding effect.

[0083] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A laser composite-roll annealing method for high-strength steel and stainless steel composite plates, characterized in that: The steps include: S1. Nano-treatment of stainless steel surface: The surface of the stainless steel plate to be composited is strengthened by an ultrasonic rolling device, and the microhardness of the surface of the stainless steel plate to be composited after the treatment is 220 to 380 HV, and the depth of the treatment layer is 150 to 200 μm; S2. Laser pretreatment of high-strength steel surface: A copper integrating mirror is used to homogenize the spot energy distribution to obtain a preheating spot with a flat-top energy distribution. Combined with the temperature control of a pyrometer, the surface of the high-strength steel plate to be composited is softened and pretreated. After the treatment, the microhardness of the surface of the high-strength steel plate to be composited is reduced to 200-400 HV. S3, Laser compound: The stainless steel plate with surface hardening after ultrasonic rolling and the high-strength steel plate with surface softening pretreatment by laser irradiation are fed into the composite rollers, and layered composite is achieved under the action of the auxiliary composite processing laser beam to obtain a high-strength steel stainless steel composite plate; S4, online roll annealing: The high-strength steel and stainless steel composite plates after laser composite processing enter the roller annealing device to simultaneously achieve the bonding strength improvement, annealing and leveling of the composite plates; The roller annealing device consists of a warm pressing mechanism and a hot straightening mechanism. The hot straightening mechanism consists of an induction heating module, an air cooling device, and a leveling work roll. After the high-strength steel stainless steel composite plate passes through the warm pressing mechanism, it is first annealed using the induction heating module, then enters the air cooling device for cooling, and finally enters the leveling work roll for leveling.

2. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 1, characterized in that: In step S2, when the tensile strength of the high-strength steel plate is 500-800 MPa, the width of the preheating spot is set to 2-3 mm, the maximum surface heating temperature of the preheating spot irradiation area is 400-550°C, and the microhardness of the surface of the high-strength steel plate to be composited after treatment is reduced to 200-290 HV.

3. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 2, characterized in that: The distance between the preheating spot in step S2 and the auxiliary composite processing laser spot in step S3 is 2 to 3 mm.

4. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 1, characterized in that: In step S2, when the tensile strength of the high-strength steel plate is greater than 800 MPa, the width of the preheating spot is set to 3-5 mm, the maximum surface heating temperature of the preheating spot irradiation area is 500-700°C, and the microhardness of the surface of the high-strength steel plate to be composited after treatment is reduced to 320-400 HV.

5. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 4, characterized in that: The distance between the preheating spot in step S2 and the auxiliary composite processing laser spot in step S3 is ≤1.5 mm.

6. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 1, characterized in that: In step S1 , during the processing of the ultrasonic rolling device, the ultrasonic rolling static pressure is 200-400N, the ultrasonic frequency is 20-40kHZ, and the ultrasonic amplitude is 5-7μm.

7. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 1, characterized in that: In step S3, the power of the auxiliary composite processing laser beam is 1300-2500W, the rolling composite speed is 0.5-2.8 mm / s, and the reduction rate is 33-60%.

8. The laser composite-roll annealing method for high-strength steel and stainless steel composite plates according to claim 1, characterized in that: The temperature pressing mechanism is composed of multiple roller systems with a diameter of 160-200 mm and induction coils arranged inside the rollers. The surface temperature of the rollers is 230-400° C. and the reduction rate of each roller system is 3-5%.

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