Preparation method of single-sided stainless steel composite plate

Abstract

The application relates to a preparation method of a single-face stainless steel composite plate and belongs to the technical field of composite steel plate preparation. The method comprises the following steps: composite blank preparation, heating, rolling, cooling and coiling; the composite blank preparation step comprises a carbon structural steel base material and a stainless steel composite material, the length of the base material is L1, the length of the composite material is L2, L1=L2+(400-500) mm, and the head and tail of the composite blank in the length direction are both made of the carbon structural steel; the heating step is that the base material is on the top and the composite material is on the bottom, the temperature is heated to 1170-1220 DEG C, and the lower surface temperature is 15-25 DEG C higher than the upper surface temperature; the rolling step is that the asynchronous rolling technology is adopted in the rough rolling stage, the upper and lower roller speed ratio R1 is 0.83-0.85, and the upper and lower roller speed ratio R2 is 0.8-0.82. The application can effectively improve the buckling head caused by the different materials of the upper and lower surfaces in the rolling process, and can realize the batch continuous production of the single-face stainless steel composite plate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of composite steel plate preparation, and particularly relates to a preparation method of single-sided stainless steel composite plate. BACKGROUND

[0002] The stainless steel composite plate is widely used in bridge templates, water pipe networks, container storage tanks, mechanical equipment, clean workshops, cross-sea bridges, offshore drilling and wind power platforms, petroleum and petrochemical industries, power plants, automobiles, ships, aviation, construction, household appliances and other fields due to its high strength, good corrosion resistance, lightweight, aesthetic and practical characteristics, and belongs to green steel. Compared with single metal material, the stainless steel composite plate has significant advantages, but the production of the stainless steel composite plate is difficult. In addition to ensuring good interface bonding force, the accurate setting of the heating, rolling and cooling process parameters is also required due to the difference in thermal plasticity of different materials.

[0003] In order to ensure the flat shape of the plate strip and achieve smooth rolling, the mainstream method for producing single-sided stainless steel composite plate is to brush a separating agent between the upper and lower two composite blanks for symmetrical structure rolling, which can effectively avoid the stacking of steel strips due to buckling of the head during the rolling process. However, this method has complex production procedures, and due to the use of two-layer composite blanks for heating and rolling, the thickness of the composite blank is larger, the single pass reduction rate is smaller during the rolling process, the interface bonding is poorer, and the mechanical properties and service life of the product are affected.

[0004] The patent application with the publication number CN116944240 A discloses a production method of stainless steel composite plate with a shear strength of 400Mpa or more. The composite plate assembly method of the patent is to use two base blanks and two composite stainless steel blanks, and a separating agent needs to be brushed between the two composite blanks. After rolling is completed, the composite plate needs to be separated and cleaned, which is a complex process with high cost. In addition, the thickness of the plate blank is larger compared with the asymmetric composite, the pass reduction rate is smaller due to the limitation of the rolling mill capacity, and the interface bonding is poorer.

[0005] The patent application with the publication number CN116160753 A discloses a single-sided stainless steel composite plate and a preparation method thereof. The plate shape control of the single-sided stainless steel composite plate is realized by strictly controlling the roll speed ratio of the lower roll and the upper roll and the roll diameter difference ΔΦ of each finishing mill within different ranges. The roll diameter difference of the seven finishing mills is extremely strict, the production cost is high, the production efficiency is low, and the buckling of the head caused by the difference in material quality of the base material and the composite material is difficult to completely solve. SUMMARY

[0006] To solve the above technical problems, the present application provides a preparation method of single-sided stainless steel composite plate, which simplifies the complicated process of existing stainless steel composite plate rolling, can obtain stainless steel composite plate with good rolling plate shape and excellent interface bonding rate, and has high production efficiency and is suitable for batch production.

[0007] To achieve the above-mentioned purposes, the technical scheme adopted by the present application is:

[0008] A preparation method of a single-sided stainless steel composite plate, comprising a composite blank preparation, heating, rolling, cooling and coiling process;

[0009] The composite blank preparation process, the composite blank comprises a carbon structural steel base material and a stainless steel composite material, the thickness ratio of the composite material to the base material is 1:(4-12), the length of the base material is L1, the length of the composite material is L2, L1=L2+(400-500)mm, and the head and tail ends of the composite blank in the length direction are both single-material carbon structural steel;

[0010] In the heating process, the carbon structural steel base material is on the top and the stainless steel composite material is on the bottom, and the heating temperature is 1170-1220℃, and the lower surface temperature is 15-25℃ higher than the upper surface temperature;

[0011] In the rolling process, hot continuous rolling is carried out on a hot continuous rolling mill, and the two rough rolling mills are R1 and R2, the speed ratio of the upper and lower rollers of R1 is 0.83-0.85, and the speed ratio of the upper and lower rollers of R2 is 0.8-0.82.

[0012] Further, in the composite blank preparation process, the surfaces to be combined of the base material and the composite material are cleaned, finely smoothed and polished, and the composite is pressed and welded around, and multi-layer and multi-pass welding is carried out, and the temperature between layers is controlled within 150°; after welding, the combined surface of the base material and the composite material is vacuumized to obtain the composite blank.

[0013] Further, in the composite blank preparation process, after welding, a gas hole is left at one end of the composite blank, and a steel pipe is welded outside the gas hole, the composite blank is vacuumized through the steel pipe, and the steel pipe opening is closed to ensure that the vacuum degree is ≤0.1Pa.

[0014] Further, in the composite blank preparation process, the surfaces to be combined of the base material and the composite material are finely smoothed and polished to an average surface roughness Ra≤0.5μm and a maximum roughness Ry≤4.0μm.

[0015] Further, in the heating process, the total heating time is t=(1-1.3)×(H1+H2), and the soaking time is 30-50min;

[0016] In the formula, t is the total heating time, min;

[0017] H1 is the thickness of the base material, mm;

[0018] H2 is the thickness of the composite material, mm.

[0019] Further, the rolling process, R1 is carried out for 3 passes of rough rolling, the rolling speed is 1.2-1.5 m / s, R2 is carried out for 3-5 passes of rough rolling, the rolling speed is 2.5-2.8 m / s, the single pass reduction rate of the first three passes in the rough rolling stage is all greater than or equal to 17%.

[0020] Further, the rolling process, the intermediate blank thickness is 35-50 mm; the edge induction heating is started in the intermediate blank temperature control process, the heating temperature is set to be 25-50 DEG C, seven-stand continuous rolling is carried out by adopting F1-F7 finishing rolling mills, the edgewise roll reducing amount is 0 mm, the cooling water between the last three finishing rolling mill stands is closed, and the finish rolling temperature is 875-900 DEG C.

[0021] Further, the cooling and coiling process, the laminar flow cooling equipment is adopted to control the cooling of the rolled composite plate, the edge shielding is adopted in the cooling process, the single edge shielding width is 30 mm, the cooling speed is 15-25 DEG C / s, and the coiling temperature is 640-660 DEG C.

[0022] Further, the thickness of the composite plate finished product is 4-25 mm, and the width is 840-2060 mm.

[0023] The composite blank preparation process in the application is mainly based on the following considerations:

[0024] a. The length of the composite plate blank is designed as carbon steel plate blank length L1>stainless steel plate blank length L2, and L1=L2+(400-500) mm, that is, the head and tail of the steel strip are rolled into carbon steel single material, which has two reasons, one is that the plasticity parameters of stainless steel and carbon structural steel are different, the upper and lower surface metals are plastically deformed under the rolling force in the rolling process, the steel strip is prone to serious head-off, and thus is stuck into the under part of the roller bed to cause rolling waste, in order to avoid the serious head-off of the steel strip in the rolling process, the head and tail of the plate blank are made of carbon steel single material; the other reason is that after the steel strip is completed coiling, the steel coil is loose in the cooling process due to the different shrinkage rates of the upper and lower surfaces of the different materials, which causes the subsequent opening process to be unable to be carried out, and the head and tail of the steel strip are made of carbon steel single material, which can effectively prevent the steel coil from being loose.

[0025] b. The upper and lower surface differential temperature heating process is adopted, which is because the plasticity of the stainless steel layer is lower than that of the carbon steel in the high temperature state, and the upper and lower surfaces are heated at different temperatures, which is beneficial to the uniform and cooperative deformation of the upper and lower two layers of materials in the rolling process.

[0026] c. The asynchronous rolling technology is adopted in the rough rolling stage, the upper and lower rolling speed ratio of R1 is 0.83-0.85, and the upper and lower rolling speed ratio of R2 is 0.8-0.82, which aims to make the upper and lower two layers of metal materials adopt different linear speeds to realize the same plastic deformation, so as to ensure the flatness of the plate in the rolling process.

[0027] The beneficial effects of the present application are:

[0028] (1) The present application provides a preparation method of single-sided stainless steel composite plate strip with carbon structural steel as the base body, which simplifies the complicated process of using a brushing separating agent for rolling of two-layer composite plates and separation after edge cutting, greatly improves the production efficiency, and is more conducive to deformation penetration and higher composite interface bonding rate.

[0029] (2) The present application adopts a group blanking mode with the base material blank length greater than the composite material length, and combines the upper and lower temperature difference heating with the upper and lower roller asynchronous rolling process, which can effectively improve the buckling head caused by the different materials of the upper and lower surfaces during rolling, and is conducive to realizing batch continuous production of single-sided stainless steel composite plates. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of the composite blank prepared by the present application;

[0031] In the figure, L1 is the length of the carbon structural steel base material, H1 is the thickness of the carbon structural steel base material, L2 is the length of the stainless steel composite material, and H2 is the thickness of the stainless steel composite material. DETAILED DESCRIPTION

[0032] Example 1: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0033] 1) Composite blank preparation:

[0034] The base material Q235 has a size of 150mmx1540mmx9300mm, and the composite material 304 stainless steel blank has a size of 30mmx1510mmx8900mm. The surfaces to be combined of the base material and the composite material are cleaned, and then finely smoothed and polished by an automatic plane polisher. The average roughness of the material surface is Ra=0.4μm, and the maximum roughness is Ry=3.3μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is sequentially performed by using a submerged arc welding machine, and the interlayer temperature is controlled to be ≤150°. After welding, a hole is drilled at the end of the plate blank to perform vacuumizing, and the vacuum degree is 0.1Pa. After vacuumizing, the air hole is sealed.

[0035] 2) Composite plate blank heating:

[0036] The composite plate blank is heated, and the stainless steel surface is downward and the carbon steel surface is upward. The total heating time is 180min, and the soaking time is 30min. The upper surface temperature of the plate blank after discharging is 1170℃, and the lower surface temperature of the plate blank after discharging is 1185℃.

[0037] 3) Composite plate blank rolling:

[0038] The finished thickness of the roll-bonded steel plate is set to 6 mm and the width is 1540 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 is subjected to 3 passes of rough rolling, the rolling speed is 1.3 m / s, the speed ratio of the upper and lower rolls of R1 is 0.83, R2 is subjected to 3 passes of rough rolling, the rolling speed is 2.6 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.8, the single pass reduction rate of the first three passes in the rough rolling stage is 21%, 17.8%, and 18.1% respectively, and the intermediate blank thickness is 42 mm.

[0039] The temperature control process of the intermediate blank is started, the heating temperature is set to 50℃, the temperature uniformity in the width direction of the steel plate is ensured, the seven-stand continuous rolling mill F1-F7 is used for finish rolling, the edger roller reduction is 0 mm, the cooling water between the last three stands of the finish rolling mill is turned off, and the finish rolling temperature is 895℃.

[0040] 4) Cooling and coiling:

[0041] The laminar flow cooling equipment is used for controlled cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used during the cooling process, the single edge shielding width is 30 mm, the cooling speed is 21.5℃ / s, and the coiling temperature is 643℃.

[0042] Example 2: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0043] 1) Composite blank preparation:

[0044] The size of the base material Q235 is 160 mm x 2040 mm x 7900 mm, and the size of the composite 304 stainless steel blank is 40 mm x 2040 mm x 7500 mm. The surfaces to be combined of the base material and the composite are cleaned, and then finely smoothed and polished by an automatic flat polishing machine. The average roughness of the material surface is Ra=0.3 μm, and the maximum roughness is Ry=3.6 μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is performed by a submerged arc welding machine, the temperature between the layers is controlled within 150°, and after welding, a hole is drilled at the end of the plate blank for vacuumizing, the vacuum degree is 0.05 Pa, and the air hole is sealed after vacuumizing.

[0045] 2) Composite plate blank heating:

[0046] The composite plate blank is heated, with the stainless steel surface facing down and the carbon steel surface facing up. The total heating time is 230 min, and the soaking time is 40 min. The upper surface temperature of the plate blank after exiting the furnace is 1180℃, and the lower surface temperature after exiting the furnace is 1200℃.

[0047] 3) Composite plate blank rolling:

[0048] The finished thickness of the rolled composite steel plate is set to 10 mm, and the width is 2040 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 performs 3 passes of rough rolling, the rolling speed is 1.4 m / s, the speed ratio of the upper and lower rolls of R1 is 0.84, R2 performs 5 passes of rough rolling, the rolling speed is 2.7 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.81, the single pass reduction rates of the first three passes in the rough rolling stage are 17.5%, 18.3%, and 17.9% respectively, and the intermediate blank thickness is 48 mm.

[0049] The temperature control process of the intermediate blank is started, the heating temperature is set to 25℃, the temperature uniformity in the width direction of the steel plate is ensured, seven-stand continuous rolling is performed by F1-F7 finishing mills, the edger roll reduction is 0 mm, the cooling water between the last three finishing mill stands is turned off, and the finishing temperature is 899℃.

[0050] 4) Cooling and coiling:

[0051] The laminar flow cooling equipment is used to control the cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used during the cooling process, the single edge shielding width is 30 mm, the cooling speed is 20℃ / s, and the coiling temperature is 651℃.

[0052] Example 3: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0053] 1) Composite blank preparation:

[0054] The size of the base material Q235 is 189 mm x 1860 mm x 10800 mm, and the size of the composite material 304 stainless steel is 21 mm x 1860 mm x 10380 mm. The surfaces to be combined of the base material and the composite material are cleaned, and then finely smoothed and polished by an automatic flat polishing machine. The average roughness of the material surface is Ra=0.5 μm, and the maximum roughness is Ry=4.0 μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is performed by a submerged arc welding machine, the temperature between the layers is controlled within 150°, and after welding, a hole is drilled at the end of the plate blank for vacuumizing, the vacuum degree is 0.07 Pa, and the hole is sealed after vacuumizing.

[0055] 2) Composite plate blank heating:

[0056] The composite plate blank is heated, and the stainless steel surface is downward and the carbon steel surface is upward. The total heating time is 245 min, the soaking time is 42 min, the upper surface temperature of the plate blank after discharging is 1198℃, and the lower surface temperature after discharging is 1221℃.

[0057] 3) Composite plate blank rolling:

[0058] The finished thickness of the rolled composite steel plate is set to 6 mm, and the width is 2040 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 performs 3 passes of rough rolling, the rolling speed is 1.36 m / s, the speed ratio of the upper and lower rolls of R1 is 0.83, R2 performs 5 passes of rough rolling, the rolling speed is 2.62 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.81, the single pass reduction rate of the first three passes in the rough rolling stage is 17.6%, 18.3%, and 18.1% respectively, and the intermediate blank thickness is 47 mm.

[0059] The temperature control process of the intermediate blank is started, the heating temperature is set to 40℃, the temperature uniformity in the width direction of the steel plate is ensured, seven-stand continuous rolling is performed by F1-F7 finishing mills, the edger roll reduction is 0 mm, the cooling water between the last three finishing mill stands is turned off, and the finishing temperature is 895℃.

[0060] 4) Cooling and coiling:

[0061] The laminar flow cooling equipment is used to control the cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used during the cooling process, the single edge shielding width is 30 mm, the cooling speed is 22℃ / s, and the coiling temperature is 646℃.

[0062] Example 4: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0063] 1) Composite blank preparation:

[0064] The size of the base material Q235 is 204 mm x 2060 mm x 7650 mm, and the size of the composite 304 stainless steel blank is 17 mm x 2060 mm x 7200 mm. The surfaces to be combined of the base material and the composite are cleaned, and then finely smoothed and polished by an automatic flat polishing machine. The average roughness of the material surface is Ra=0.5 μm, and the maximum roughness is Ry=2.8 μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is performed by a submerged arc welding machine, the temperature between the layers is controlled within 150℃, and after welding, a hole is drilled at the end of the plate blank for vacuumizing, the vacuum degree is 0.04 Pa, and the air hole is sealed after vacuumizing.

[0065] 2) Composite plate blank heating:

[0066] The composite plate blank is heated, with the stainless steel surface facing down and the carbon steel surface facing up. The total heating time is 287 min, the soaking time is 50 min, the upper surface temperature of the plate blank after discharging is 1195℃, and the lower surface temperature after discharging is 1220℃.

[0067] 3) Composite plate blank rolling:

[0068] The finished thickness of the rolled composite steel plate is set to 16 mm, and the width is 2060 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 performs 3 passes of rough rolling, the rolling speed is 1.5 m / s, the speed ratio of the upper and lower rolls of R1 is 0.85, R2 performs 5 passes of rough rolling, the rolling speed is 2.8 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.82, the single pass reduction rate of the first three passes in the rough rolling stage is 17.4%, 19%, and 18.8% respectively, and the intermediate blank thickness is 49 mm.

[0069] The temperature control process of the intermediate blank is started, the heating temperature is set to 50℃, the temperature uniformity in the width direction of the steel plate is ensured, the seven-stand continuous rolling mill is used for finish rolling, which is F1-F7, the edger roll reduction is 0 mm, the cooling water between the last three stands of finish rolling mills is turned off, and the finish rolling temperature is 875℃.

[0070] 4) Cooling and coiling:

[0071] The laminar flow cooling equipment is used for controlled cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used in the cooling process, the single edge shielding width is 30 mm, the cooling speed is 18℃ / s, and the coiling temperature is 648℃.

[0072] Example 5: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0073] 1) Composite blank preparation:

[0074] The size of the base material Q235 is 154 mm x 840 mm x 7940 mm, and the size of the composite 304 stainless steel blank is 22 mm x 840 mm x 7500 mm. The surfaces to be combined of the base material and the composite are cleaned, and then finely smoothed and polished by an automatic flat polishing machine. The average roughness of the material surface is Ra=0.4 μm, and the maximum roughness is Ry=3.0 μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is performed by a submerged arc welding machine, the temperature between the layers is controlled within 150°, and after welding, a hole is drilled at the end of the plate blank for vacuumizing, the vacuum degree is 0.1 Pa, and the hole is sealed after vacuumizing.

[0075] 2) Composite plate blank heating:

[0076] The composite plate blank is heated, with the stainless steel surface facing down and the carbon steel surface facing up. The total heating time is 185 min, and the soaking time is 35 min. The upper surface temperature of the plate blank after discharging is 1170℃, and the lower surface temperature after discharging is 1185℃.

[0077] 3) Composite plate blank rolling:

[0078] The finished thickness of the rolled composite steel plate is set to 4 mm, and the width is 840 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 performs 3 passes of rough rolling, the rolling speed is 1.2 m / s, the speed ratio of the upper and lower rolls of R1 is 0.83, R2 performs 3 passes of rough rolling, the rolling speed is 2.5 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.80, the single pass reduction rate of the first three passes in the rough rolling stage is 17%, 18.4% and 18.1% respectively, and the intermediate blank thickness is 35 mm.

[0079] The temperature control process of the intermediate blank is started, the heating temperature is set to 40℃, the temperature uniformity in the width direction of the steel plate is ensured, the seven-stand continuous rolling mill is used for finish rolling, which is F1-F7, the edger roll reduction is 0 mm, the cooling water between the last three stands of finish rolling mills is turned off, and the finish rolling temperature is 900℃.

[0080] 4) Cooling and coiling:

[0081] The laminar flow cooling equipment is used for controlled cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used in the cooling process, the single edge shielding width is 30 mm, the cooling speed is 25℃ / s, and the coiling temperature is 660℃.

[0082] Example 6: Method for preparing a composite plate of Q235 carbon structural steel base material + 304 stainless steel composite material

[0083] 1) Composite blank preparation:

[0084] The size of the base material Q235 is 220 mm x 1560 mm x 7640 mm, and the size of the composite 304 stainless steel blank is 20 mm x 1560 mm x 7140 mm. The surfaces to be combined of the base material and the composite are cleaned, and then finely smoothed and polished by an automatic flat polishing machine. The average roughness of the material surface is Ra=0.3 μm, and the maximum roughness is Ry=2.5 μm. The two surfaces to be combined are opposite, and a composite plate blank automatic hydraulic forming machine with a pressure of 1000 tons is used to press the two kinds of plate blanks to form a composite, and then the periphery is ring welded. A multi-layer multi-pass welding is performed by a submerged arc welding machine, the temperature between the layers is controlled within 150℃, and after welding, a hole is drilled at the end of the plate blank for vacuumizing, the vacuum degree is 0.06 Pa, and the air hole is sealed after vacuumizing.

[0085] 2) Composite plate blank heating:

[0086] The composite plate blank is heated, and the stainless steel surface faces downward and the carbon steel surface faces upward. The total heating time is 290 min, and the soaking time is 50 min. The upper surface temperature of the plate blank after discharging is 1182℃, and the lower surface temperature after discharging is 1207℃.

[0087] 3) Composite plate blank rolling:

[0088] The finished thickness of the rolled composite steel plate is set to 25 mm, and the width is 1560 mm. The heated composite blank is subjected to hot continuous rolling on a hot continuous rolling mill. The two rough rolling mills are R1 and R2, R1 performs 3 passes of rough rolling, the rolling speed is 1.38 m / s, the speed ratio of the upper and lower rolls of R1 is 0.84, R2 performs 5 passes of rough rolling, the rolling speed is 2.62 m / s, and the speed ratio of the upper and lower rolls of R2 is 0.81, the single pass reduction rate of the first three passes in the rough rolling stage is 17.2%, 17.7%, and 17.9% respectively, and the intermediate blank thickness is 50 mm.

[0089] The edge induction heating is started in the intermediate blank temperature control process, the heating temperature is set to 25℃, the temperature uniformity in the width direction of the steel plate is ensured, the seven-stand continuous rolling mill is used for finish rolling, which is F1-F7, the edger roll reduction is 0 mm, the cooling water between the last three stands of finish rolling mills is turned off, and the finish rolling temperature is 875℃.

[0090] 4) Cooling and coiling:

[0091] The laminar flow cooling equipment is used for controlled cooling of the rolled steel strip, in order to prevent excessive cooling of the edge, the edge shielding is used in the cooling process, the single edge shielding width is 30 mm, the cooling speed is 15℃ / s, and the coiling temperature is 640℃.

[0092] The mechanical properties of the composite plates obtained in each example are detected according to the GB / T6396-2008 standard, and the results are shown in Table 1, which meet the requirements of the GB / T8165-2008 standard.

[0093] Table 1 Mechanical property test results of the composite plates of each example

[0094]

Claims

1. A method for manufacturing a single-sided stainless steel clad plate, characterized by: It comprises a composite blank preparation, heating, rolling, cooling and coiling process; The composite blank preparation process, the composite blank comprises two layers of carbon structural steel base material and stainless steel composite material, the thickness ratio of the composite material to the base material is 1: (4-12), the length of the base material is L1, the length of the composite material is L2, L1=L2+ (400-500) mm, and the head and tail ends of the composite blank in the length direction are both of carbon structural steel single material; The heating process, the carbon structural steel base material is on the top, and the stainless steel composite material is on the bottom, and the heating temperature is 1170-1220℃, and the lower surface temperature is 15-25℃ higher than the upper surface temperature; The rolling process, hot continuous rolling is carried out on a hot continuous rolling mill, two rough rolling mills are R1 and R2 respectively, the speed ratio of the upper and lower rollers of R1 is 0.83-0.85, and the speed ratio of the upper and lower rollers of R2 is 0.8-0.82; R1 carries out 3 passes of rough rolling, and the rolling speed is 1.2-1.5 m / s, R2 carries out 3-5 passes of rough rolling, and the rolling speed is 2.5-2.8 m / s, the single pass reduction rate of the first three passes in the rough rolling stage is ≥17%; the intermediate blank thickness is 35-50 mm; the intermediate blank temperature control process opens the edge induction heating, the heating temperature is set to 25-50℃, seven-stand continuous rolling is carried out by using F1-F7 finishing rolling mills, the edger roller reduction amount is 0 mm, the cooling water between the last three finishing mill stands is closed, and the final rolling temperature is 875-900℃.

2. The method of claim 1, wherein the single-sided stainless steel clad plate is prepared by the steps of: The composite blank preparation process, the surface of the base material and the composite material to be combined is cleaned, finely smoothed and polished, and the composite is pressed, and the periphery is ring welded, and multi-layer and multi-pass welding is carried out, and the interlayer temperature is controlled within 150°; after welding, the combined surface of the base material and the composite material is vacuumized to obtain the composite blank. ​ 3. The method of claim 2, wherein the stainless steel clad plate is prepared by the steps of: The composite blank preparation process, after welding, a gas hole is left at one end of the composite blank, and a steel pipe is welded outside the gas hole, the composite blank is vacuumized through the steel pipe, and the steel pipe opening is closed, so that the vacuum degree is ≤0.1 Pa. ​ 4. The method of claim 3, wherein the stainless steel clad plate is prepared by the steps of: The composite blank preparation process, the surface of the base material and the composite material to be combined is cleaned, finely smoothed and polished, and the composite is pressed, and the periphery is ring welded, and multi-layer and multi-pass welding is carried out, and the interlayer temperature is controlled within 150°; after welding, the combined surface of the base material and the composite material is vacuumized to obtain the composite blank. ​ 5. The method of claim 4, wherein the stainless steel clad plate is prepared by the steps of: The heating process, the total heating time is t= (1-1.3) × (H1+H2), and the soaking time is 30-50 min; ​ In the formula, t is the total heating time, min; H1 is the thickness of the base material, mm; H2 is the thickness of the composite material, mm.

6. The method of claim 5, wherein the stainless steel clad plate is prepared by the steps of: The cooling and coiling process, laminar flow cooling equipment is used to control the cooling of the rolled composite plate, the cooling process adopts edge shielding, the single edge shielding width is 30 mm, the cooling speed is 15-25℃ / s, and the coiling temperature is 640-660℃. ​ 7. The method of claim 1-6, wherein the method is characterized by, The thickness of the finished composite plate is 4-25 mm, and the width is 840-2060 mm.

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