A method for preparing single-sided stainless steel composite sheet coil

Abstract

This invention discloses a method for preparing single-sided stainless steel composite sheet coils, relating to the field of single-sided stainless steel composite sheet coil production technology. Through the synergistic effects of precise thickness design in asymmetrical billet assembly, uniform heating in the furnace, multi-pass precise rolling in a hot continuous rolling mill, and controllable coiling, the finished cladding thickness is controlled to meet set requirements. The uncovered area at the edge of the cladding is controlled within a limited width, and the cladding billet does not undergo sensitization during production, maintaining good corrosion resistance. Ultimately, a composite sheet coil meeting industrial application requirements is obtained. This method yields single-sided stainless steel composite sheet coils with a cladding thickness accuracy of ±0.1mm, an uncovered width at the edge of the cladding ≤10mm, and excellent corrosion resistance of the cladding stainless steel.

Description

Technical Field

[0001] This invention relates to the field of single-sided stainless steel composite sheet and coil production technology, specifically to a method for preparing single-sided stainless steel composite sheet and coil; more specifically, to a full-process production strategy for stainless steel composite coils with high dimensional accuracy, high yield, and excellent corrosion resistance of the cladding stainless steel. Background Technology

[0002] Currently, the hot continuous rolling process for single-sided stainless steel composite plates offers significant advantages over traditional single-plate rolling processes, including higher production efficiency, higher yield, and greater flexibility in product specifications, making it a promising candidate for industrial production. However, under existing technologies, the actual thickness of the composite slab in the finished single-sided stainless steel composite plate coil deviates considerably from the target thickness. Furthermore, relevant technologies for this hot continuous rolling process are scarce, and a systematic process technology that can meet the product quality stability requirements of industrial production remains undeveloped. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method for preparing single-sided stainless steel composite sheet coils, which overcomes the defect of large error between the actual thickness and the target thickness of the cladding in the finished composite sheet, and enables the thickness control accuracy of the cladding in the finished product to meet the set requirements.

[0004] In view of this, the present invention provides a method for preparing a single-sided stainless steel composite sheet coil, comprising the following steps:

[0005] S100, Asymmetrical assembly: The composite blank is formed by bonding one side of the cladding blank and the base blank together; wherein, before bonding, the design thickness of the cladding blank in the composite blank is calculated using the following formula (1). ,

[0006] (1)

[0007] In the formula, This refers to the design thickness of the multi-layer slab in the composite billet. This represents the calculated thickness of the multi-layered slab in the composite billet. Indicates the rolling deformation temperature of the multilayer slab. Rheological stress under the following conditions Indicates the rolling deformation temperature of the base slab. Rheological stress under the following conditions This represents the thickness compensation value of the multi-layer slab in the composite billet. Indicates the design thickness of the composite billet. This indicates the target thickness of the multilayer slab in the finished product. Indicates the target thickness of the finished product. and These are all calculation coefficients for the thickness of the multi-layer slab in the composite billet. Indicates the rolling deformation temperature;

[0008] S200, Heating in a heating furnace: The combined billet is fed into a heating furnace for heating;

[0009] S300, Hot continuous rolling mill rolling: The heated composite billet is taken out of the furnace and sent to the hot continuous rolling mill for rough rolling;

[0010] S400, Winding machine winding: After the rough rolling is completed, the winding is carried out, the end is cut off and the finished product is output.

[0011] According to some embodiments of the present invention, in step S100, the materials of the cladding slab and the base slab are first selected, and a hot compression test is performed; based on the results of the hot compression test, the material is determined. , , and The numerical values ​​ensure the rationality of this invention.

[0012] According to some embodiments of the present invention, in the hot compression test, the deformation temperature is set in the range of 500℃ to 1200℃, and the strain rate is set in the range of 0.5 / s to 10 / s.

[0013] According to some embodiments of the present invention, in step S200, the time required for the temperature of the composite billet to rise from 200°C to 1200°C during the heating process is at least 150 minutes. This is to address the problem that the large difference in thermal expansion coefficients between the stainless steel layer and the carbon steel layer during heating can cause bulging in the stainless steel layer after exiting the furnace, affecting rolling.

[0014] According to some embodiments of the present invention, in step S200, the furnace exit temperature of the composite billet is set to 1200°C to 1220°C, and the holding time at the furnace exit temperature of the composite billet is 30 min to 45 min. This ensures that the precipitated phases in the base plate of the composite billet are fully dissolved during the heating process.

[0015] According to some embodiments of the present invention, the rough rolling in S300 includes at least five passes, wherein the reduction rate of the first pass is 16% to 20%. This is to ensure that the strip does not separate during the rough rolling process and to achieve preliminary bonding.

[0016] According to some embodiments of the present invention, in the third to fifth passes, the side width reduction of the vertical rolls of the hot strip mill is 5mm to 10mm; the side width reduction of the vertical rolls of the hot strip mill cannot be performed in the first and second passes. This is to improve the problem of no multilayer coverage in the 15mm to 25mm width range of the combined billet surface.

[0017] According to some embodiments of the present invention, during rough rolling in S300, the asynchronous rate of the work rolls of the hot continuous rolling mill is 5%~12%. This is to suppress the warping caused by the asymmetric deformation of the base slab and the cladding slab during rough rolling.

[0018] According to some embodiments of the present invention, during winding in S400, the winding temperature is 400°C to 500°C. This is to suppress the sensitization effect of the stainless steel cladding, while also considering the capabilities of the winding equipment; and to avoid the sensitization temperature range of austenitic stainless steel (500°C to 850°C) to prevent the cladding from experiencing a decrease in corrosion resistance due to sensitization.

[0019] According to some embodiments of the present invention, in step S100, the width of the cladding slab is smaller than the width of the base slab slab, with a width difference of 5mm to 15mm; during bonding, the cladding slab slab is centrally positioned on one side of the base slab slab, with its edges parallel and aligned. This solves the problem of no cladding layer covering the edges in traditional technologies, ensuring uniform stress on the cladding and base layers during rolling, reducing uneven local deformation caused by cladding position offset, thereby reducing the risk of interface separation and plate warping, and providing a stable foundation for subsequent rolling processes.

[0020] This invention has at least the following technical effects:

[0021] 1. This invention achieves precise thickness control of the finished cladding by employing asymmetric billet assembly, uniform heating in a furnace, multi-pass precise rolling in a hot continuous rolling mill, and controllable coiling. This ensures the cladding thickness is precisely controlled to meet set requirements, the uncovered area at the edges is kept within a defined width, and the cladding does not undergo sensitization during production, maintaining good corrosion resistance. Ultimately, a composite finished plate coil meeting industrial application requirements is obtained. Practical experience has demonstrated that this method for preparing single-sided stainless steel composite plate coils yields cladding thickness accuracy of ±0.1mm, uncovered edge width ≤10mm, and excellent corrosion resistance (no sensitization) of the cladding stainless steel.

[0022] 2. This invention obtains the rheological stress values ​​of the cladding and the base cladding at different temperatures through hot compression tests, and determines the calculation coefficient of the thickness of the cladding in the composite blank through fitting calculation, as well as the design thickness formula (1) of the cladding in the composite blank. This solves the problem of large error between the actual thickness and the target thickness of the cladding in the finished composite board, and makes the thickness control accuracy of the finished cladding reach the set requirements.

[0023] 3. In this invention, for different materials (multilayer / base layer) or finished product specifications, the appropriate parameters are obtained through the same hot compression test and data fitting logic, without the need for re-exploration, thus improving the versatility of this preparation method.

[0024] 4. In this invention, by designing the precise thickness ratio of the asymmetric billet, that is, the design thickness formula (1) of the cladding in the composite billet, the interface separation caused by improper thickness matching during rolling is avoided, thus providing a prerequisite for subsequent rolling composite.

[0025] 5. In this invention, by controlling the heating rate, the time required for the composite billet to rise from the initial temperature to the target temperature is ensured to meet the requirements, so that the base plate and the cladding plate are fully heated, avoiding uneven thermal expansion or oxidation defects at the interface caused by excessively rapid heating.

[0026] 6. In this invention, by controlling the heat preservation time, the temperature of each part of the composite billet is ensured to be uniform, creating conditions for uniform deformation in subsequent rolling; by heat preservation at high temperature, the base layer is completely dissolved, improving the plasticity and toughness of the base layer, avoiding cracking caused by the brittleness of the base layer during rolling, and helping to improve the composite quality of the finished product.

[0027] 7. In this invention, the first pass uses a moderate reduction rate, and the reduction rate of subsequent passes is adjusted according to process requirements; the rolling speed gradually increases with each pass to reduce the temperature drop difference of the composite billet during rolling; and the forming and compounding of the composite billet are completed collaboratively. Moreover, the third to fifth passes use the vertical rolls of the hot strip mill for side pressure widening, with the vertical rolls applying side pressure according to a set program; the first and second passes do not use vertical roll side pressure widening to avoid edge deformation and instability of the composite billet due to its large thickness, or delamination caused by the interface not being firmly bonded.

[0028] 8. In this invention, by setting a suitable winding temperature, the loose roll shape caused by high-temperature winding is avoided, and the hard and brittle base layer structure caused by low-temperature winding is prevented. At the same time, the capability of the winding equipment is matched to ensure stable continuous industrial production.

[0029] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a flowchart of a method for preparing a single-sided stainless steel composite sheet coil according to the present invention;

[0032] Figure 2 This is a graph showing the ratio of the finished product to the composite layer in Example 2 of the present invention.

[0033] Figure 3 This is a graph showing the relationship between strip length and coiling temperature in Embodiment 2 of the present invention.

[0034] The purpose, features, and advantages of this accompanying drawing will be further explained in conjunction with the embodiments and with reference to the accompanying drawing. Detailed Implementation

[0035] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0036] Example 1

[0037] See Figure 1 As shown, a method for preparing a single-sided stainless steel composite plate coil according to the present invention includes steps S100 asymmetric billet assembly, S200 furnace heating, S300 hot continuous rolling, and S400 coiling, as described below:

[0038] S100, Asymmetrical assembly: The composite blank is formed by bonding one side of the cladding blank and the base blank together; wherein, before bonding, the design thickness of the cladding blank in the composite blank is calculated using the following formula (1). ,

[0039] (1)

[0040] In the formula, This refers to the design thickness of the multi-layer slab in the composite billet. This represents the calculated thickness of the multi-layered slab in the composite billet. Indicates the rolling deformation temperature of the multilayer slab. Rheological stress under the following conditions Indicates the rolling deformation temperature of the base slab. Rheological stress under the following conditions This represents the thickness compensation value of the multi-layer slab in the composite billet. Indicates the design thickness of the composite billet. This indicates the target thickness of the multilayer slab in the finished product. Indicates the target thickness of the finished product. and These are all calculation coefficients for the thickness of the multi-layer slab in the composite billet. This indicates the rolling deformation temperature.

[0041] Specifically, step S100 includes S110, S120, S130, S140, and S150:

[0042] S110. Material Selection: Select the materials for the base plate and the cladding plate according to the requirements of the finished product, and prepare the materials according to the selected materials.

[0043] S120. Hot Compression Test: After selecting the materials of the cladding slab and the base slab, samples are cut from both slabs; these are processed into standard samples required for the hot compression test, and then the hot compression test is conducted using a thermal simulation testing machine. During the test, the rolling deformation temperature in the subsequent rolling process is simulated. Based on deformation rate conditions, multiple sets of mechanical property data, such as stress data, are obtained for the composite slab and the base slab under corresponding working conditions.

[0044] In one specific embodiment, the base plate accounts for 5% to 50% of the composite blank, the deformation temperature is set in the range of 500℃ to 1200℃, and the strain rate is set in the range of 0.5 / s to 10 / s.

[0045] S130. Determine parameter values: Based on the multiple sets of stress data obtained from the hot compression test in S120, regression analysis is performed. The calculation coefficients a and b for the thickness of the cladding in the composite billet, as well as the rheological stress values ​​of the cladding at different temperatures, are determined through fitting calculations. rheological stress values ​​of the base slab Determine the rolling opening degree based on the hot strip mill. The value. Determine based on actual needs. and The value.

[0046] S140, Thickness Formula Calculation: [The following is a partial translation of the original text, which is not possible without , , , , and Substitute the numerical value into the following preset formula (1),

[0047] (1)

[0048] Calculate the thickness of the multi-layer slab in the composite billet sequentially. Thickness compensation value of multi-layer slabs in composite billets Finally, the design thickness of the multi-layer slab in the composite billet was obtained. .

[0049] Furthermore, S130 includes S131 and S132; specifically, S131 is for calculating The value is compared with the value 1; S132 is when... hour, Moreover, the rolling deformation temperature The value ranges from 500℃ to 1200℃. When hour, Moreover, the rolling deformation temperature The value is between 500℃ and 1200℃.

[0050] S150, Slab bonding: The composite slab is formed by bonding one side of the cladding slab and the base slab. During bonding, ensure that the bonding surfaces of the cladding slab and the base slab are aligned and that the edge misalignment is controlled within the allowable range. After bonding, spot welding is used to fix the slab to prevent relative sliding or separation of the interface during the rolling process.

[0051] Specifically, the width of the cladding slab is smaller than the width of the base slab slab, with a width difference of 5mm to 15mm; during bonding, the cladding slab slab is centered on one side of the base slab slab, with its edges parallel and aligned.

[0052] The rheological stress values ​​of the multilayer slab at different temperatures were obtained through hot compression tests. rheological stress values ​​of the base slab By fitting calculations, the calculation coefficients a and b of the thickness of the cladding in the composite billet are determined, as well as the calculation formula (1) for the design thickness of the cladding in the composite billet. This completely solves the problem of large error between the actual thickness and the target thickness of the cladding in the finished composite plate, and enables the thickness control accuracy of the finished cladding to meet the set requirements. Furthermore, for different materials (cladding / base layer) or finished product specifications, the appropriate parameters are obtained through the same hot compression test and data fitting logic, eliminating the need for re-exploration and improving the versatility of this preparation method. In this invention, the precise thickness ratio design of the asymmetric billet assembly, i.e., the calculation formula (1) for the design thickness of the cladding in the composite billet, avoids interface separation caused by improper thickness matching during rolling, providing a prerequisite for subsequent rolling composite.

[0053] S200, Heating in a heating furnace: The assembled billet is fed into a heating furnace for heating. Specifically, step S200 includes S210 and S220; wherein,

[0054] S210. Heating of the composite billet: The composite billet obtained in S100 after bonding is sent to the heating furnace for heating. The heating furnace adopts a segmented heating mode, gradually heating according to the preset heating curve, controlling the heating rate, and passing through the preheating and heating stages in sequence to ensure that the time taken for the composite billet to rise from the initial temperature to the target temperature meets the requirements, so that the base plate billet and the cladding billet are fully heated, avoiding uneven thermal expansion or oxidation defects at the interface caused by excessively rapid heating.

[0055] Furthermore, during the heating process in S210, the time required for the temperature of the composite billet to rise from 200°C to 1200°C is at least 150 minutes.

[0056] S220. Composite billet heat preservation: After the composite billet is heated to the set furnace exit temperature, it is kept at this temperature for a period of time for heat preservation. During the heat preservation process, the surface temperature of the composite billet is monitored in real time by a temperature measuring device, and the power of the heating furnace is adjusted in a timely manner to ensure that the temperature of each part of the composite billet is uniform, thus creating conditions for uniform deformation in subsequent rolling.

[0057] Furthermore, during the heat preservation process in S220, the furnace exit temperature of the composite billet is set at 1200℃ to 1220℃, and the heat preservation time of the composite billet at the furnace exit temperature is 30min to 45min.

[0058] S300, Hot Continuous Rolling Mill Rolling: The heated composite billet is taken out of the furnace and sent to the hot continuous rolling mill for rough rolling.

[0059] Specifically, rough rolling is carried out in a set number of passes, and the reduction rate of each pass is allocated according to the thickness of the composite billet and the finished product requirements. The first pass adopts a moderate reduction rate, and the reduction rate of subsequent passes is adjusted according to process requirements. The rolling speed is gradually increased with each pass to reduce the temperature drop difference of the composite billet during the rolling process. The composite billet is formed and compounded in a coordinated manner.

[0060] Furthermore, the third to fifth passes are widened by side pressure using the vertical rolls of the hot strip mill, with the vertical rolls applying side pressure according to a set program; the first and second passes are not widened by side pressure using the vertical rolls, in order to avoid edge deformation and instability of the combined billet due to its large thickness, or delamination caused by the interface not being firmly bonded.

[0061] Furthermore, the hot strip mill uses an asynchronous rolling mode for its work rolls. By setting the speed difference between the upper and lower roll lines, an asynchronous rate is formed. The additional shear force generated by asynchronous rolling promotes the plastic fusion of the interface between the cladding slab and the base slab. At the same time, the asynchronous rate is controlled within a reasonable range to avoid slippage or slab shape defects.

[0062] S400, Winding machine winding: After the rough rolling is completed, the winding is carried out, the end is cut off and the finished product is output.

[0063] Specifically, after rough rolling, the composite billet is cooled to the set coiling temperature by the cooling system and then sent to the coiler for coiling. During the cooling process, the cooling rate is controlled to avoid structural defects caused by excessive cooling of the cladding stainless steel. When coiling, an appropriate coiling tension is set to ensure the stability of the base layer structure and to ensure the regularity of the coil shape. After coiling, the irregular parts at the ends of the billet are cut off to obtain the finished product.

[0064] This invention achieves precise thickness control of the cladding layer by employing asymmetric billet assembly, uniform heating in a furnace, multi-pass precision rolling in a hot continuous rolling mill, and controllable coiling. This ensures the finished cladding layer achieves the set thickness requirements, keeps the uncovered area at the edges within a defined width, and prevents sensitization of the cladding layer during production, maintaining good corrosion resistance. Ultimately, this yields a composite finished plate coil that meets the requirements for industrial applications. This method for preparing single-sided stainless steel composite plate coils yields a cladding layer thickness accuracy of ±0.1mm, an uncovered width at the edges ≤10mm, and excellent corrosion resistance (no sensitization) of the cladding stainless steel.

[0065] Example 2

[0066] S110. Material Selection: Based on the finished product requirements: produce 304+Q235B single-sided stainless steel composite coils, with a target thickness of 1mm (304) + 15mm (Q235B); the base slab material is selected as Q235B, with a thickness of 200mm; the cladding slab material is selected as 304 stainless steel, and materials are prepared according to the selected materials. That is, For 16mm and It is 1mm.

[0067] S120. Hot Compression Test: After selecting the materials for the cladding and base slabs, samples are taken from the central area of ​​both cladding and base slabs and machined into small cylindrical specimens with a diameter of 10 mm and a height of 15 mm. These specimens are then placed in a thermal simulation testing machine for a hot compression test. The test includes heating, holding, and compression stages. First, during the heating process, the rolling deformation temperature is simulated for the subsequent rolling process. Take respectively The temperatures were 900℃, 1000℃, and 1100℃. During the heat preservation process, the holding time was 3-5 minutes. During the compression process, the strain rate was set to 8 / s. Rheological stress data of the cladding slab and the base slab at 900℃, 1000℃, and 1100℃ were obtained to determine... = 171.1, = 121.3, = 90.3, =198.4, = 136.6, = 99.7.

[0068] S130. Determine parameter values: Based on the multiple sets of stress data obtained from the hot compression test in S120, regression analysis is performed to obtain... Figure 2 The curve showing the relationship between the finished product and the proportion of the cladding in the composite billet is given. The compression ratio is 92.5%, and the calculation coefficients for the thickness of the cladding in the composite billet are a=0.9649 and b=-0.0044.

[0069] exist Figure 2 In the figure, the fitting formula is marked as y = 0.9649x - 0.0044 (R²=0.9958), where x is the "proportion of strata in the composite billet" and y is the "proportion of strata in the finished product". Finally, the calculation coefficients for the thickness of the strata slab in the composite billet are determined as a=0.9649 and b=-0.0044. Figure 2 Linear fitting was performed using multiple sets of hot compression test data (the correspondence between the proportion of cladding layers in the composite billet and the proportion of cladding layers in the finished product), and R² = 0.9958 (close to 1), proving that the data reliability of the fitting relationship is extremely high. This indicates that the calculation coefficients a and b for the thickness of the cladding layers in the composite billet are based on objective experimental results, and proves the design thickness for calculating the cladding layers in the composite billet. Equation (1) is not empirical and has rationality.

[0070] Furthermore, adjustments to the materials of the multilayer / base layer or the specifications of the finished product can also be made in other production scenarios. Figure 2 The "proportion relationship logic" uses the same hot compression test and fitting method to obtain the calculation coefficients a and b of the thickness of the multilayer slab in the suitable composite billet, rather than exploring the parameters again, which shows that the preparation method is reproducible.

[0071] and, Figure 2 The fitted curve is used for subsequent calculations of the design thickness of the multi-layer slab in the composite billet. The basis of formula (1): Only when the calculation coefficients a and b of the thickness of the strata slab in the composite billet are accurate can the design thickness of the strata slab in the composite billet be calculated by formula (1). This ensures that the thickness of the cladding layer in the finished product after rolling hits the target (such as the target thickness of 1mm required in this embodiment), and ensures that the accuracy of the cladding layer thickness in the finished product obtained by this method is controlled within ±0.1mm.

[0072] Determine based on the rolling opening of the hot strip mill The range is 180mm to 250mm, here we take... It is 215mm.

[0073] S140, Thickness Formula Calculation: [The following is a partial translation of the original text, which is not possible without and Substitute the values In the middle, we get:

[0074] ,

[0075] therefore: .

[0076] Based on the above, we set a=0.9649, b=-0.0044, =16mm =1mm and Substituting 215 into equation (1), the calculated thickness of the strata slab in the composite billet is calculated sequentially. Thickness compensation value of multi-layer slabs in composite billets Finally, the design thickness of the multi-layer slab in the composite billet was obtained. The specific calculation process is as follows:

[0077] .

[0078] S150, Slab bonding: The composite slab is formed by bonding one side of the cladding slab and the base slab. During bonding, ensure that the bonding surfaces of the cladding slab and the base slab are aligned and that the edge misalignment is controlled within the allowable range. After bonding, spot welding is used to fix the slab to prevent relative sliding or separation of the interface during the rolling process.

[0079] S210. Heating of the composite billet: The composite billet obtained in S150 after bonding is sent to the heating furnace for heating. The heating furnace adopts a segmented heating mode, gradually increasing the temperature according to the preset heating curve, controlling the heating rate. The time for the composite billet temperature to rise from 200℃ to 1200℃ is 155 minutes.

[0080] S220, Combined billet heat preservation: After the combined billet is heated to the set furnace exit temperature, it is kept at this temperature for a period of time for heat preservation. During the heat preservation process, the surface temperature of the combined billet is monitored in real time by a temperature measuring device, and the power of the heating furnace is adjusted in time to ensure that the temperature of each part of the combined billet is uniform. The furnace exit temperature of the combined billet is 1220℃, and the heat preservation time between 1200℃ and 1220℃ is 38 minutes.

[0081] S300, Hot Continuous Rolling Mill Rolling: The heated composite billet is taken out of the furnace and sent to the hot continuous rolling mill for rough rolling. The working roll asynchronous rate of the hot continuous rolling mill is 7%. The rough rolling includes five passes. The first pass of rough rolling has a reduction rate of 18%. The vertical roll width is reduced by 8mm in the third to fifth passes of rough rolling, and the width reduction is 0mm in the first to second passes.

[0082] S400, Coiling: After rough rolling, coiling is performed. The target coiling temperature is 450℃, but it fluctuates between 400℃ and 500℃ in practice. Finally, the ends are trimmed before outputting the finished product. The relationship between strip length and coiling temperature is as follows: Figure 3 As shown, this indicates that the cladding layer of the single-sided stainless steel composite sheet coil produced in this embodiment did not undergo sensitization.

[0083] Figure 3 The horizontal axis represents the "strip length", and the vertical axis represents the "winding temperature". The curve shows that the actual winding temperature fluctuates between 400℃ and 500℃ (target temperature 450℃). Figure 3The results showed that the temperature remained stable within the target range throughout the entire strip length, demonstrating that the integrated heating furnace-rolling-cooling process can precisely control the coiling temperature and eliminates the risk of sensitization due to localized overheating. Furthermore, salt spray testing was conducted during actual production. Following the salt spray tests, the cladding layer's corrosion resistance was compared to pure 304 stainless steel. The results showed that the cladding layer of the single-sided stainless steel composite coil in this embodiment exhibited corrosion resistance comparable to pure 304. Photos were taken during the experiment, and the comparative images were archived.

[0084] and, Figure 3 The length dimension of the covered strip indicates that not only the temperature at a single point meets the standard, but the coiling temperature of the entire strip has small fluctuations and is stable. This proves that the preparation method of single-sided stainless steel composite plate coil in this embodiment can be used for large-scale continuous production, rather than small-batch laboratory verification, and has industrial application value.

[0085] The method provided in this embodiment produces 1mm+15mm 304+Q235B single-sided stainless steel composite coils on a 1580 hot continuous rolling line. The cladding thickness of the steel coil reaches the target of 1mm with a tolerance of ±0.1mm (photos were taken during the experiment, and comparative photos were archived). The width of the edge of the steel coil not covered with stainless steel is ≤2mm, with almost complete coverage, which is better than the 20mm produced by traditional processes, increasing the yield by 3 percentage points. Moreover, no sensitization occurred in the composite cladding, and the corrosion resistance is comparable to pure 304. The above results indicate that the method for producing stainless steel composite plates in this invention can significantly improve the product yield, ensure the accuracy of the cladding thickness, and enhance the corrosion resistance of the cladding.

[0086] The above content is merely a modification or supplement to the structure of the present invention or a substitution in a similar manner. As long as it does not deviate from the structure of the invention or exceed the scope defined in the claims, it shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a single-sided stainless steel composite sheet / coil, characterized in that, Includes the following steps: S100, Asymmetrical assembly: The composite blank is formed by bonding one side of the cladding blank and the base blank together; wherein, before bonding, the design thickness of the cladding blank in the composite blank is calculated using the following formula (1). , （1） In the formula, This refers to the design thickness of the multi-layer slab in the composite billet. This represents the calculated thickness of the multi-layered slab in the composite billet. Indicates the rolling deformation temperature of the multilayer slab. Rheological stress under the following conditions Indicates the rolling deformation temperature of the base slab. Rheological stress under the following conditions This represents the thickness compensation value of the multi-layer slab in the composite billet. Indicates the design thickness of the composite billet. This indicates the target thickness of the multilayer slab in the finished product. Indicates the target thickness of the finished product. and These are all calculation coefficients for the thickness of the multi-layer slab in the composite billet. Indicates the rolling deformation temperature; S200, Heating in a heating furnace: The combined billet is fed into a heating furnace for heating; S300, Hot continuous rolling mill rolling: The heated composite billet is taken out of the furnace and sent to the hot continuous rolling mill for rough rolling; S400, Winding machine winding: After the rough rolling is completed, the winding is carried out, the end is cut off and the finished product is output.

2. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, In step S100, the materials of the cladding slab and the base slab are first selected, and a hot compression test is conducted; based on the results of the hot compression test, the material is determined. , , and The value.

3. The method for preparing a single-sided stainless steel composite sheet coil according to claim 2, characterized in that, In the hot compression test, the deformation temperature is set in the range of 500℃ to 1200℃, and the strain rate is set in the range of 0.5 / s to 10 / s.

4. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, In S200, during the heating process, the time required for the temperature of the composite billet to rise from 200°C to 1200°C is at least 150 minutes.

5. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, In step S200, the furnace exit temperature of the composite billet is set to 1200℃ to 1220℃, and the holding time for the furnace exit temperature of the composite billet is 30min to 45min.

6. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, When rough rolling is performed in the S300, it includes at least five rolling passes, wherein the reduction rate of the first pass is 16% to 20%.

7. The method for preparing a single-sided stainless steel composite sheet coil according to claim 6, characterized in that, In the third to fifth passes, the side pressure of the vertical rolls of the hot strip mill is reduced by 5mm to 10mm; the side pressure of the vertical rolls of the hot strip mill cannot be reduced in the first and second passes.

8. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, During rough rolling in S300, the asynchronous rate of the work rolls of the hot strip mill is 5%~12%.

9. The method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, During the winding process in S400, the winding temperature is 400℃~500℃.

10. A method for preparing a single-sided stainless steel composite sheet coil according to claim 1, characterized in that, In step S100, the width of the composite slab is less than the width of the base slab, and the width difference is 5mm to 15mm; during bonding, the composite slab is centered on one side of the base slab, and the edges are parallel and aligned.

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