A pickling process for 309S stainless steel wide hot-rolled coil

Abstract

The invention discloses a pickling process for a 309S stainless steel wide band hot continuous rolling coil, and the process steps are as follows: 1) prepare a steel billet to be heated in a heating furnace, and the heating steps are sequentially divided into a preheating section, a heating section, a second heating section, and a soaking section; 2) high-pressure water descaling; 3) rough rolling: the heated steel billet is transmitted to a rough rolling mill through a transmission roller; 4) finishing rolling: it enters a finishing rolling mechanism after transmission; 5) coiling: after finishing rolling, it is sent to a coiling mechanism for coiling; 6) uncoiling and welding: two adjacent groups of stainless steel plates are welded and fixed by a welding mechanism, so as to facilitate the overall pickling of the stainless steel plates; 7) annealing; 8) phosphorus-breaking shot blasting; 9) pickling: the stainless steel plates are pickled and scale removed by a pickling mechanism; 10) cleaning and drying: the stainless steel plates after pickling are cleaned by a cleaning mechanism. The invention can reduce the phenomenon of cracking on the rolling surface and improve the pickling effect of the stainless steel plate surface.

Description

Technical Field

[0001] The invention belongs to the technical field of stainless steel plate coil rolling, and particularly relates to a pickling process for 309S stainless steel wide band hot-rolled plate coil. Background Art

[0002] 309S stainless steel is a chromium-nickel austenitic stainless steel with a higher chromium-nickel content than 304. It can effectively control the formation of oxides at high temperatures. Compared with ferrite and martensitic heat-resistant steels with body-centered cubic structures, 309S stainless steel has better comprehensive properties such as high-temperature oxidation resistance and high-temperature creep strength. This stainless steel is widely used, mainly in high-temperature furnaces, petrochemicals, machinery industry, aerospace and other fields.

[0003] 1) 309S heat-resistant austenitic stainless steel has high Cr and Ni contents (Cr% + Ni% > 45%) and is a high value-added steel. Due to the high Cr and Ni contents, the ingot has a coarse columnar crystal structure, and it is difficult to control the oxygen and sulfur content and inclusions of the steel. It has high thermal sensitivity and is prone to cracking. Due to the narrow hot working temperature range, low high temperature plasticity, and high deformation resistance, it is easy to cause cracking on the plate surface during hot rolling.

[0004] 2) Since the surface oxide scale structure is complex and dense after annealing, the surface is prone to roughness and poor pickling after pickling; therefore, 309S heat-resistant austenitic stainless steel is developed and produced, and its reasonable production process is studied, especially the key process technologies of steelmaking, continuous casting, hot rolling, heat treatment and pickling are mastered;

[0005] 3) After pickling, the surface of the stainless steel plate will be cleaned by rinsing, brushing, squeezing, drying and other steps; if there are residual water stains and acid on the surface, the surface quality of the stainless steel plate will be seriously affected. If the plate surface is simply rinsed, the effect will be unsatisfactory, and multiple rinsing processes will be required, which is inefficient. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a pickling process for 309S stainless steel wide band hot-rolled coil, which can reduce the cracking phenomenon of the rolled surface and improve the pickling effect of the stainless steel plate surface.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A pickling process for 309S stainless steel wide hot-rolled coil, the process steps are as follows:

[0009] 1) Prepare the steel billet to be heated in a heating furnace, and the heating steps are divided into a preheating section, a heating section, a second heating section, and a soaking section in sequence; in the preheating section, the temperature is controlled at 550-620°C, and the heating time is 100-120min; after the preheating section is completed, the steel billet enters the first heating section for heating, and the temperature is controlled at 950-1050°C, and the heating time is 60-70min; after the first heating section is completed, the steel billet enters the second heating section for heating, and the temperature is controlled at 1250-1270°C, and the heating time is 55-55min; after the second heating section is completed, the steel billet enters the soaking section, and the temperature is controlled at 1250-1260°C, and the heating time is 40-50min; the total heating time is 255-295min.

[0010] 2) High-pressure water descaling: the oxide scale on the surface of the heated steel billet is removed by a high-pressure water jet mechanism.

[0011] 3) Rough rolling: The heated billet is transferred to the rough rolling mill through a transfer roller, and a corresponding heat preservation cover is provided on the transfer device; the billet is rolled in 7 passes during rough rolling; the first pass reduction rate is 29-30.5%; the second pass reduction rate is 23.5-25%; the third pass reduction rate is 23.5-25%; the fourth pass reduction rate is 26-27%; the fifth pass reduction rate is 27-28.5%; the sixth pass reduction rate is 27-28.5%; the seventh pass reduction rate is 29-30.5%;

[0012] 4) Finishing rolling: After transmission, it enters the finishing rolling mechanism, and the finishing rolling adopts speed-increasing rolling. The starting temperature of the finishing rolling is set at 1050-1070℃; the ending temperature of the finishing rolling is 950-1050℃.

[0013] 5) Coiling: After finishing rolling, the steel is sent to the coiling mechanism for coiling.

[0014] 6) Uncoiling and welding: The two adjacent sets of stainless steel plates are welded and fixed by the welding mechanism to facilitate the overall pickling of the stainless steel plates.

[0015] 7) Annealing: The stainless steel plate is annealed by an annealing mechanism and then cooled.

[0016] 8) Phosphorus-breaking shot blasting: The annealed stainless steel plate is shot blasted by a shot blasting machine.

[0017] 9) Pickling: The stainless steel plate is pickled by a pickling mechanism to remove the oxide scale; the pickling process is provided with a mixed acid stage and a mixed acid stage; the mixed acid stage has an HNO3 concentration of 75-80g / L, an HF concentration of 30-40g / L, metal ions <40g / L, and a temperature of 50-60°C; the mixed acid stage has an HNO3 concentration of 50-60g / L, an HF concentration of 30-35g / L, metal ions of 25-45g / L, and a temperature of 50-55°C.

[0018] 10) Cleaning and drying: The pickled stainless steel plate is cleaned by a cleaning mechanism, and then dried by a drying system before curling.

[0019] In step 10), the cleaning mechanism includes a scrubbing pool, a scrubbing mechanism I, a flushing mechanism I, a flushing mechanism II, and a scrubbing mechanism II; the scrubbing mechanism I, the scrubbing mechanism II, the flushing mechanism I, and the flushing mechanism II are arranged in the scrubbing pool; the scrubbing pool is provided with flushing mechanism II, scrubbing mechanism II, flushing mechanism I, and scrubbing mechanism I from top to bottom in sequence; inlet and outlet are provided at both ends of the scrubbing pool, guide roller I is provided at the inlet and outlet, and guide roller II is provided inside the scrubbing pool.

[0020] The scrubbing mechanism I comprises a motor I, a fixed plate I, a transmission shaft, a fixed arm I, a fixed shaft I, a fixed arm II, a scrubbing roller, and a fixed frame; the motor I is fixed to the outer wall of the scrubbing pool through a motor seat, a bevel gear is provided on the shaft of the motor I, a pair of fixed plate I is provided, which are respectively located on both sides of the motor I and fixedly connected to the scrubbing pool, and both ends of the transmission shaft are rotatably connected to the fixed plate I, and a bevel gear is provided on the transmission shaft and meshes with the bevel gear on the shaft of the motor I; a pair of fixed arms I are provided and respectively fixed at both ends of the transmission shaft, one end of the fixed shaft I is fixedly connected to the fixed arm I, and the other end of the fixed shaft I is rotatably connected to the fixed arm II; One end of the fixed arm II is rotatably connected to the scrubbing roller, and both ends of the scrubbing roller are rotatably connected to the scrubbing pool through guide sleeves and bearings; the scrubbing roller includes a roller body I, a connecting shaft, and a pressure plate, and both ends of the roller body I are provided with a fixed shaft II, and one end of the fixed shaft II is provided with a guide groove and a mounting groove, one end of the connecting shaft is provided with a limit plate, and the other end is rotatably connected to the side wall of the scrubbing pool through the guide sleeve, the limit plate is arranged in the mounting groove, the pressure plate is arranged in a semicircular shape, and the pressure plate is provided with a pair of fixed shafts II and connected by bolts; the fixed frame is arranged on the inner wall of the scrubbing pool, and guide columns are arranged at both ends of the fixed frame, and one end of the guide column is arranged in the guide groove.

[0021] The flushing mechanism I includes a motor II, a fixed arm III, a connecting arm, a fixed arm V, a fixed shaft III, a water spray pipe, and a fixed shaft V; the motor II is fixed to the outer wall of the scrubbing tank through a fixing seat and is located above the motor I, one end of the fixed arm III is fixedly connected to the shaft end of the motor II, and the other end is fixedly connected to the fixed shaft V, a pair of water spray pipes are provided and are respectively located on both sides of the motor II, the water spray pipes are rotatably connected to the side walls of the scrubbing tank, the fixed arm V is provided with a pair of water spray pipes that are respectively fixedly connected, the fixed shaft III is provided with a pair of fixedly connected fixed arms V, and the connecting arm is provided with a pair of fixedly connected fixed shafts III and fixed shafts V, respectively; the water spray pipe is provided above the scrubbing roller, and one end of the water spray pipe is connected to an external water supply system through a rotating joint, including a water reservoir and a water pump.

[0022] The brushing mechanism II and the brushing mechanism I have the same structure, the brushing roller in the brushing mechanism I is arranged on one side of the stainless steel plate, and the brushing roller in the brushing mechanism II is arranged on the other side of the stainless steel plate; the flushing mechanism II and the flushing mechanism I have the same structure, the water spray pipe in the flushing mechanism I is arranged on one side of the stainless steel plate, and the water spray pipe in the flushing mechanism II is arranged on the other side of the stainless steel plate.

[0023] Preferably, an improved scheme for the scrubbing roller, the scrubbing roller comprises a rotating shaft, an insert, a fixed plate II, a threaded rod, a roller body II, and a gear; one end of the rotating shaft is provided with a guide groove and a mounting groove and is rotatably connected to the connecting shaft through a pressure plate, the rotating shaft body is provided with a number of evenly distributed slots, a number of gears are provided and are respectively arranged in the slots and are rotatably connected to the rotating shaft through a fixed shaft; the roller body II is formed by a combination of a number of fan-shaped blocks, the fan-shaped blocks correspond to the slots, and the fan-shaped blocks are provided with ear plates; the insert is provided with a number of groups, each group is provided with a pair and symmetrically arranged in the slots, the insert is provided with a through groove, a support arm, and a rack, the rack is provided at one end of the insert and meshes with the gear, the support arm is provided in the through groove, one end of the support arm is hinged to the insert, and the other end is hinged to the ear plate; the fixed plate II is fixedly connected to one end of the insert by a bolt, the threaded rod passes through the fixed plate II, the threaded rod is connected to the fixed plate II by a thread, and one end of the threaded rod is rotatably connected to one end of the rotating shaft.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The motor I provides power to drive the transmission shaft to rotate, and then the fixed arm I and the fixed arm II pull the scrubbing roller to slide back and forth. At the same time, during the sliding process, the guide column and the guide groove drive the roller body I to rotate, so that the scrubbing is more uniform and comprehensive, which promotes the scrubbing effect of the scrubbing roller on the stainless steel plate and further improves the pickling effect of the stainless steel surface;

[0026] 2) In the improved scrubbing roller, the rotating shaft is pushed by rotating the threaded rod, thereby pulling the insert to slide along the slot, and then through the cooperation of the gear and the rack, a pair of inserts in the slot slide in opposite directions along the slot, and then the roller body II is pushed to rise or reset through the support arm, thereby completing the adjustment of the outer diameter of the roller body II to adapt to the scrubbing of stainless steel plates of different thicknesses; the rotating shaft and the insert pass through the side wall of the scrubbing pool and are rotatably connected through the guide sleeve and the bearing; the cleaning of the stainless steel plate surface is greatly improved through scrubbing and flushing, and the quality of the stainless steel plate surface is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Attached Figure 1 It is a structural schematic diagram of a cleaning mechanism in a pickling process of a 309S stainless steel wide band hot-rolled coil according to the present invention;

[0028] Attached Figure 2 Yes Figure 1 Schematic diagram of the position structure of the middle flushing mechanism II and the brushing mechanism II;

[0029] Attached Figure 3 Yes Figure 1 Schematic diagram of the internal structure of the middle scrubbing pool Figure 1 ;

[0030] Attached Figure 4 Yes Figure 1 Schematic diagram of the internal structure of the middle scrubbing pool Figure 2 ;

[0031] Attached Figure 5 Yes Figure 1 Structural schematic diagram of the middle scrubbing mechanism Ⅰ and the flushing mechanism Ⅰ;

[0032] Attached Figure 6 Yes Figure 5 A magnified schematic diagram of the local structure in FIG.

[0033] Attached Figure 7 Yes Figure 6 Structure diagram of the middle brush roller Figure 1 ;

[0034] Attached Figure 8 Yes Figure 6 Structure diagram of the middle brush roller Figure 2 ;

[0035] Attached Fig. 9 Yes Figure 6 Schematic diagram of the structure of the middle water spray pipe;

[0036] Attached Fig.10 Yes Figure 1 Structural schematic diagram of the middle flushing mechanism I;

[0037] Attached Fig.11 Yes Figure 6 Structure diagram of the middle brush roller Figure 3 ;

[0038] Attached Fig.12 Yes Fig.11 A schematic diagram of the structure of the rotating shaft;

[0039] Attached Fig.13 Yes Fig.11 Schematic diagram of the structure of the middle cutting;

[0040] Attached Fig.14 Yes Fig.11 Schematic diagram of the exploded structure of the middle roller body II;

[0041] Attached Fig.15 Yes Fig.11 Bottom view of the connection between the middle insert and roller body II;

[0042] Attached Fig.16 Yes Fig.15A magnified schematic diagram of the local structure;

[0043] Attached Fig.17 Yes Fig.11 Schematic diagram of the adjustment effect of the middle rack and roller body II;

[0044] In the figure: 1, scrubbing tank; 101, guide roller I; 102, guide roller II; 2, scrubbing mechanism I; 201, motor I; 202, fixed plate I; 203, transmission shaft; 204, fixed arm I; 205, fixed shaft I; 206, fixed arm II; 207, scrubbing roller; 2071, roller body I; 20711, fixed shaft II; 20712, guide groove; 20713, mounting groove; 2072, connecting shaft; 20721, limit plate; 2073, pressure plate; 2074, rotating shaft; 20741, slot; 2075 , insert; 20751, through groove; 20752, support arm; 20753, rack; 2076, fixed plate II; 2077, threaded rod; 2078, roller body II; 20781, ear plate; 2079, gear; 208, fixed frame; 2081, guide column; 3, flushing mechanism I; 301, motor II; 302, fixed arm III; 303, connecting arm; 304, fixed arm V; 305, fixed shaft III; 306, water spray pipe; 307, fixed shaft V; 4, flushing mechanism II; 5, scrubbing mechanism II; 6, stainless steel plate. DETAILED DESCRIPTION

[0045] To facilitate the understanding of those skilled in the art, Figure 1-17 , the technical solution of the present invention is further specifically described.

[0046] Embodiment 1:

[0047] A pickling process for 309S stainless steel wide hot-rolled coil, the process steps are as follows:

[0048] 1) Prepare the steel billet to be heated in the heating furnace, and the heating steps are divided into preheating section, heating section, heating section and soaking section in sequence; in the preheating section, the temperature is controlled at 600°C and the heating time is 112min; after the preheating section is completed, enter the heating section for heating, the temperature is controlled at 980°C and the heating time is 66min; after the heating section is completed, enter the heating section for heating, the temperature is controlled at 1254.5°C and the heating time is 53min; after the heating section is completed, enter the soaking section, the temperature is controlled at 1255°C and the heating time is 48min; the total heating time is 279min.

[0049] 2) High-pressure water descaling: the oxide scale on the surface of the heated steel billet is removed by a high-pressure water jet mechanism.

[0050] 3) Rough rolling: The heated billet is transferred to the rough rolling mill through the transfer roller, and a corresponding heat preservation cover is provided on the transfer device; the billet is rolled in 7 passes during the rough rolling; the first pass has a reduction rate of 29.2%; the second pass has a reduction rate of 24.5%; the third pass has a reduction rate of 24.2%; the fourth pass has a reduction rate of 26.3%; the fifth pass has a reduction rate of 27.8%; the sixth pass has a reduction rate of 27.5%; the seventh pass has a reduction rate of 29.5%;

[0051] 4) Finishing rolling: After transmission, it enters the finishing rolling mechanism, and the finishing rolling adopts speed-increasing rolling. The starting temperature of the finishing rolling is set at 1062°C; the ending temperature of the finishing rolling is 1050°C.

[0052] 5) Coiling: After finishing rolling, the steel is sent to the coiling mechanism for coiling.

[0053] 6) Uncoiling and welding: The two adjacent sets of stainless steel plates are welded and fixed by the welding mechanism to facilitate the overall pickling of the stainless steel plates.

[0054] 7) Annealing: The stainless steel plate is annealed by an annealing mechanism and then cooled.

[0055] 8) Phosphorus-breaking shot blasting: The annealed stainless steel plate is shot blasted by a shot blasting machine.

[0056] 9) Pickling: The stainless steel plate is pickled by a pickling mechanism to remove the oxide scale; the pickling process includes a mixed acid stage and a mixed acid stage; the mixed acid stage has an HNO3 concentration of 79.5 g / L, an HF concentration of 32.5 g / L, a metal ion concentration of 35 g / L, and a temperature of 58°C; the mixed acid stage has an HNO3 concentration of 53 g / L, an HF concentration of 32.3 g / L, a metal ion concentration of 32 g / L, and a temperature of 52.8°C.

[0057] 10) Cleaning and drying: The pickled stainless steel plate is cleaned by a cleaning mechanism, and then dried by a drying system before curling.

[0058] In step 10), the cleaning mechanism includes a scrubbing pool 1, a scrubbing mechanism Ⅰ2, a flushing mechanism Ⅰ3, a flushing mechanism Ⅱ4, and a scrubbing mechanism Ⅱ5; the scrubbing mechanism Ⅰ2, the scrubbing mechanism Ⅱ5, the flushing mechanism Ⅰ3, and the flushing mechanism Ⅱ4 are arranged in the scrubbing pool 1; the scrubbing pool 1 is sequentially arranged with the flushing mechanism Ⅱ4, the scrubbing mechanism Ⅱ5, the flushing mechanism Ⅰ3, and the scrubbing mechanism Ⅰ2 from top to bottom; the scrubbing pool 1 is provided with inlets and outlets at both ends for the inlet and outlet transmission of the stainless steel plate 6, and the inlet and outlet are provided with guide rollers Ⅰ101, and the scrubbing pool 1 is provided with guide rollers Ⅱ102 for the transmission and direction change of the stainless steel plate 6.

[0059] The scrubbing mechanism I2 comprises a motor I201, a fixing plate I202, a transmission shaft 203, a fixing arm I204, a fixing shaft I205, a fixing arm II206, a scrubbing roller 207 and a fixing frame 208; the motor I201 is fixed to the outer wall of the scrubbing pool 1 through a motor seat, a bevel gear is arranged on the shaft of the motor I201, the fixing plate I202 is provided with a pair of gears respectively located on both sides of the motor I201 and fixedly connected to the scrubbing pool 1, the two ends of the transmission shaft 203 are rotatably connected to the fixing plate I202, the transmission shaft 203 is provided with a bevel gear and meshes with the motor bevel gear on the machine Ⅰ201 shaft; a pair of fixed arms Ⅰ204 are provided and are respectively fixed at both ends of the transmission shaft 203, one end of the fixed shaft Ⅰ205 is fixedly connected to the fixed arm Ⅰ204, and the other end of the fixed shaft Ⅰ205 is rotatably connected to the fixed arm Ⅱ206; one end of the fixed arm Ⅱ206 is rotatably connected to the brush roller 207, and both ends of the brush roller 207 are rotatably connected to the brush pool 1 through the guide sleeve and the bearing; the brush roller 207 includes a roller body Ⅰ2071, a connecting shaft 2072, and a pressing plate 2073, and the two ends of the roller body Ⅰ2071 are provided with fixed shafts Ⅱ20 711, a guide groove 20712 and a mounting groove 20713 are provided on a fixed shaft II 20711 at one end, a limit plate 20721 is provided at one end of the connecting shaft 2072, and the other end is rotatably connected to the side wall of the scrubbing pool 1 through a guide sleeve, the limit plate 20721 is arranged in the mounting groove 20713, the pressing plate 2073 is arranged in a semicircular shape, the pressing plate 2073 is provided with a pair of fixed shafts II 20711 connected by bolts, and then the fixed shaft II 20711 and the connecting shaft 2072 are connected; the fixing frame 208 is arranged on the inner wall of the scrubbing pool 1, Guide columns 2081 are provided at both ends of the fixed frame 208, and one end of the guide column 2081 is arranged in the guide groove 20712; the motor Ⅰ201 provides power to drive the transmission shaft 203 to rotate, and then the fixed arm Ⅰ204 and the fixed arm Ⅱ206 pull the brush roller 207 to slide back and forth in the guide sleeve, and at the same time, during the sliding process, the roller body Ⅰ2071 is driven to rotate through the action of the guide column 2081 and the guide groove 20712, so that the brushing is more uniform and comprehensive, which promotes the improvement of the brushing effect of the brush roller 207 on the stainless steel plate 6.

[0060] The flushing mechanism I3 includes a motor II301, a fixed arm III302, a connecting arm 303, a fixed arm V304, a fixed shaft III305, a water spray pipe 306, and a fixed shaft V307; the motor II301 is fixed to the outer wall of the scrubbing pool 1 through a fixing seat and is located above the motor I201, one end of the fixed arm III302 is fixedly connected to the shaft end of the motor II301, and the other end is fixedly connected to the fixed shaft V307. The water spray pipe 306 is provided with a pair and is respectively located on both sides of the motor II301, and the water spray pipe 306 is rotatably connected to the side wall of the scrubbing pool 1, and the fixed arm V304 is provided with a pair of and respectively fixedly connected to the water spray pipe 306. The fixed shaft III 305 is provided with a pair of fixed arms V 304 that are respectively fixedly connected, and the connecting arm 303 is provided with a pair of fixed shafts III 305 and fixed shafts V 307 that are respectively rotatably connected; the water spray pipe 306 is arranged above the scrubbing roller 207 and washes the stainless steel plate 6, and one end of the water spray pipe 306 is connected to an external water supply system through a rotating joint, including a water reservoir and a water pump; water is supplied through the water supply system; power is provided by the motor II 301 to drive the fixed arm III 302 to rotate, and then the water spray pipe 306 is pulled to rotate through the connecting arm 303 and the fixed arm V 304, thereby realizing the reciprocating change of the flushing angle of the water spray pipe 306.

[0061] The scrubbing mechanism Ⅰ2 cooperates with the flushing mechanism Ⅰ3 to simultaneously scrub one side of the stainless steel plate 6 with the scrubbing roller 207 and flush with the water spray pipe 306.

[0062] The brushing mechanism II5 has the same structure as the brushing mechanism I2, the brushing roller 207 in the brushing mechanism I2 is arranged on one side of the stainless steel plate 6, and the brushing roller 207 in the brushing mechanism II5 is arranged on the other side of the stainless steel plate 6; the flushing mechanism II4 has the same structure as the flushing mechanism I3, the water spray pipe 306 in the flushing mechanism I3 is arranged on one side of the stainless steel plate 6, and the water spray pipe 306 in the flushing mechanism II4 is arranged on the other side of the stainless steel plate 6; the other side of the stainless steel plate 6 is brushed and flushed by the brushing roller 207 and the water spray pipe 306.

[0063] Further, an improved solution of the scrubbing roller 207, the scrubbing roller 207 comprises a rotating shaft 2074, a plug 2075, a fixing plate II 2076, a threaded rod 2077, a roller body II 2078, and a gear 2079; one end of the rotating shaft 2074 is provided with a guide groove 20712 and a mounting groove and is rotatably connected to the connecting shaft 2072 through a pressing plate 2073, a plurality of evenly distributed slots 20741 are provided on the rotating shaft 2074 body, and the gear 2079 is provided with a plurality of slots 20741 respectively arranged in the slots 2074. 741 and connected to the rotating shaft 2074 through a fixed shaft; the roller body II 2078 is formed by a combination of a plurality of fan-shaped blocks, the fan-shaped blocks correspond to the slots 20741, and the fan-shaped blocks are provided with ear plates 20781; the inserting strips 2075 are provided with a plurality of groups, each group is provided with a pair and symmetrically arranged in the slots 20741, and the inserting strips 2075 are provided with through grooves 20751, support arms 20752, and racks 20753, the racks 20753 are provided at one end of the inserting strips 2075 and mesh with the gears 2079, and the support arms 20 752 is arranged in the through slot 20751, one end of the support arm 20752 is hinged to the inserting strip 2075, and the other end is hinged to the ear plate 20781; the fixing plate II 2076 is fixedly connected to one end of the inserting strip 2075 by bolts, the threaded rod 2077 passes through the fixing plate II 2076, the threaded rod 2077 is connected to the fixing plate II 2076 by threads, and one end of the threaded rod 2077 is rotatably connected to one end of the rotating shaft 2074; by rotating the threaded rod 2077, the rotating shaft is pushed, and then the inserting strip 2075 is pulled along the slot 2 0741 slides, and then through the cooperation of the gear 2079 and the rack 20753, a pair of inserts 2075 in the slot 20741 slides in opposite directions along the slot 20741, and then the roller body II 2078 is pushed to rise or retract and reset through the support arm 20752, thereby completing the adjustment of the outer diameter of the roller body II 2078 to adapt to the scrubbing of stainless steel plates 6 of different thicknesses; the rotating shaft 2074 and the inserts 2075 pass through the side wall of the scrubbing pool 1 and are rotatably connected through the sleeve guide sleeve and the bearing.

[0064] Embodiment 2:

[0065] The difference compared with Example 1 is that;

[0066] Wherein, in the preheating section of step 1), the temperature is controlled at 580°C and the heating time is 110min; after the preheating section is completed, the heating is started in the first heating section, the temperature is controlled at 990°C and the heating time is 62min; after the first heating section is completed, the heating is started in the second heating section, the temperature is controlled at 1259°C and the heating time is 53.5min; after the second heating section is completed, the temperature is started in the soaking section, the temperature is controlled at 1256.5°C and the heating time is 45min; the total heating time is 270.5min.

[0067] Step 3) Rough rolling: The heated steel billet is transferred to the rough rolling mill through a transfer roller, and a corresponding heat preservation cover is provided on the transfer device; the steel billet is rolled in 7 passes during the rough rolling; the first pass has a reduction rate of 29.8%; the second pass has a reduction rate of 24.2%; the third pass has a reduction rate of 24%; the fourth pass has a reduction rate of 26.5%; the fifth pass has a reduction rate of 27%; the sixth pass has a reduction rate of 28%; the seventh pass has a reduction rate of 30%;

[0068] Step 4) Finishing rolling: After being transmitted, the steel enters the finishing rolling mechanism, and the finishing rolling adopts the speed increasing rolling, and the starting rolling temperature of the finishing rolling is set to 1068°C; the finishing rolling end temperature is 1030°C.

[0069] Step 9) Pickling: The stainless steel plate is pickled by a pickling mechanism to remove the oxide scale; the pickling process includes a mixed acid stage and a mixed acid stage; the mixed acid stage has an HNO3 concentration of 80.5 g / L, an HF concentration of 33 g / L, a metal ion concentration of 36 g / L, and a temperature of 57°C; the mixed acid stage has an HNO3 concentration of 57 g / L, an HF concentration of 33.4 g / L, a metal ion concentration of 35 g / L, and a temperature of 53°C.

[0070] Embodiment 3:

[0071] The difference compared with Example 1 is that;

[0072] Wherein, in the preheating section of step 1), the temperature is controlled at 575°C and the heating time is 105min; after the preheating section is completed, the heating is started in the first heating section, the temperature is controlled at 1000°C and the heating time is 65min; after the first heating section is completed, the heating is started in the second heating section, the temperature is controlled at 1262°C and the heating time is 52min; after the second heating section is completed, the soaking section is entered, the temperature is controlled at 1258°C and the heating time is 46min; the total heating time is 268min.

[0073] Step 3) Rough rolling: The heated steel billet is transferred to the rough rolling mill through a transfer roller, and a corresponding heat preservation cover is provided on the transfer device; the steel billet is rolled in 7 passes during the rough rolling; the first pass has a reduction rate of 30%; the second pass has a reduction rate of 21%; the third pass has a reduction rate of 24.6%; the fourth pass has a reduction rate of 26.8%; the fifth pass has a reduction rate of 27.6%; the sixth pass has a reduction rate of 27.8%; the seventh pass has a reduction rate of 30.5%;

[0074] Step 4) Finishing rolling: After being transmitted, the steel enters the finishing rolling mechanism, and the finishing rolling adopts the speed increasing rolling, and the starting rolling temperature of the finishing rolling is set to 990°C; the finishing rolling end temperature is 1060°C.

[0075] Step 9) Pickling: The stainless steel plate is pickled by a pickling mechanism to remove the oxide scale; the pickling process includes a mixed acid stage and a mixed acid stage; the mixed acid stage has an HNO3 concentration of 82 g / L, an HF concentration of 34 g / L, a metal ion concentration of 32 g / L, and a temperature of 54.5°C; the mixed acid stage has an HNO3 concentration of 55.4 g / L, an HF concentration of 33.3 g / L, a metal ion concentration of 36.5 g / L, and a temperature of 54.2°C.

[0076] The difference from Example 1 is that a conventional squeezing device without online cleaning function is used in step 9);

[0077] Comparative Example 1: The plate rolled by any of Examples 1-3 is pickled by the pickling process in the patent application publication number CN113584401A, a 310S heat-resistant steel hot-rolled plate coil and its processing technology;

[0078] Comparative Example 2: The plate rolled by any of Examples 1 to 3 is pickled by the pickling process of a hot-rolled ordinary stainless steel plate pickling method in patent application publication number CN 106148973A;

[0079] The mechanical properties of the above examples were tested according to GB / 4237-2015, and the test results are shown in the following table:

[0080]

[0081] According to the above standards, the appearance quality inspection of the plate and the results are as follows:

[0082] Surface inspection results of Example 1, Example 2 and Example 3: The surface of the plate is clean, without obvious scratches, indentations, pits and other defects; there are no cracks or peeling on the surface of the plate; there is no obvious darkening or local water marks; at the same time, the surface quality of the rolled stainless steel plate is good, the plate shape is square, and the edges are neat without curling.

[0083] The surface inspection results of Comparative Examples 1 and 2: There are no obvious scratches, indentations, pits and other defects on the board surface; there are no cracks or peeling on the board surface, but there are a small number of dark spots;

[0084] According to the above conclusions, it can be known that the mechanical properties in the test results of the above-mentioned embodiments and comparative examples all meet the test standards of GB / 4237-2015; however, the surface quality of the boards in embodiments 1-3 is better, while the surface quality of the boards in comparative examples 1-2 all show different degrees of dark spots on the surface.

[0085] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A pickling process for 309S stainless steel wide hot-rolled coil, characterized in that The process steps are as follows: 1) Prepare the steel billet to be heated in a heating furnace, and the heating steps are divided into a preheating section, a heating section, a second heating section, and a soaking section; 2) High-pressure water descaling: the oxide scale on the surface of the heated steel billet is removed by a high-pressure water jet mechanism; 3) Rough rolling: The heated billet is transferred to the rough rolling mill through a transfer roller, and a corresponding heat preservation cover is provided on the transfer device; the billet is rolled in 7 passes during rough rolling; the first pass reduction rate is 29-30.5%; the second pass reduction rate is 23.5-25%; the third pass reduction rate is 23.5-25%; the fourth pass reduction rate is 26-27%; the fifth pass reduction rate is 27-28.5%; the sixth pass reduction rate is 27-28.5%; the seventh pass reduction rate is 29-30.5%; 4) Finishing rolling: After transmission, it enters the finishing rolling mechanism, and the finishing rolling adopts the speed increase rolling, and the finishing rolling starting temperature is set to 1050-1070℃; the finishing rolling ending temperature is 950-1050℃; 5) Coiling: After finishing rolling, the steel is sent to the coiling mechanism for coiling; 6) Uncoiling and welding: The two adjacent sets of stainless steel plates are welded and fixed by the welding mechanism to facilitate the overall pickling of the stainless steel plates; 7) Annealing: The stainless steel plate is annealed by an annealing mechanism and then cooled; 8) Phosphorus breaking shot blasting: Shot blasting the annealed stainless steel plate through a shot blasting machine; 9) Pickling: The stainless steel plate is pickled to remove the oxide scale through the pickling mechanism; the pickling process is provided with mixed acid stage one and mixed acid stage two; 10) Cleaning and drying: The pickled stainless steel plate is cleaned by a cleaning mechanism, and then dried by a drying system before curling; In the step 10), the cleaning mechanism comprises a scrubbing pool, a scrubbing mechanism I, a flushing mechanism I, a flushing mechanism II, and a scrubbing mechanism II; the scrubbing mechanism I, the scrubbing mechanism II, the flushing mechanism I, and the flushing mechanism II are arranged in the scrubbing pool; the scrubbing pool is provided with flushing mechanism II, scrubbing mechanism II, flushing mechanism I, and scrubbing mechanism I from top to bottom in sequence; the scrubbing pool is provided with inlets and outlets at both ends, guide rollers I are provided at the inlets and outlets, and guide rollers II are provided inside the scrubbing pool; The scrubbing mechanism I comprises a motor I, a fixed plate I, a transmission shaft, a fixed arm I, a fixed shaft I, a fixed arm II, a scrubbing roller, and a fixed frame; the motor I is fixed to the outer wall of the scrubbing pool through a motor seat, a bevel gear is provided on the shaft of the motor I, a pair of fixed plate I is provided, which are respectively located on both sides of the motor I and fixedly connected to the scrubbing pool, and both ends of the transmission shaft are rotatably connected to the fixed plate I, and a bevel gear is provided on the transmission shaft and meshes with the bevel gear on the shaft of the motor I; a pair of fixed arms I are provided and respectively fixed at both ends of the transmission shaft, one end of the fixed shaft I is fixedly connected to the fixed arm I, and the other end of the fixed shaft I is rotatably connected to the fixed arm II; One end of the fixed arm II is rotatably connected to the scrubbing roller, and both ends of the scrubbing roller are rotatably connected to the scrubbing pool through guide sleeves and bearings; the scrubbing roller comprises a roller body I, a connecting shaft, and a pressing plate, and both ends of the roller body I are provided with a fixed shaft II, and one end of the fixed shaft II is provided with a guide groove and a mounting groove, and one end of the connecting shaft is provided with a limit plate, and the other end is rotatably connected to the side wall of the scrubbing pool through the guide sleeve, and the limit plate is arranged in the mounting groove, and the pressing plate is arranged in a semicircular shape, and the pressing plate is provided with a pair of fixed shafts II and connected by bolts; the fixed frame is arranged on the inner wall of the scrubbing pool, and both ends of the fixed frame are provided with guide columns, and one end of the guide column is arranged in the guide groove; The flushing mechanism I comprises a motor II, a fixed arm III, a connecting arm, a fixed arm V, a fixed shaft III, a water spray pipe, and a fixed shaft V; the motor II is fixed to the outer wall of the scrubbing pool through a fixing seat and is located above the motor I, one end of the fixed arm III is fixedly connected to the shaft end of the motor II, and the other end is fixedly connected to the fixed shaft V, a pair of water spray pipes are provided and are respectively located on both sides of the motor II, the water spray pipes are rotatably connected to the side wall of the scrubbing pool, the fixed arm V is provided with a pair of water spray pipes that are respectively fixedly connected, the fixed shaft III is provided with a pair of fixedly connected fixed arms V, and the connecting arm is provided with a pair of fixedly connected fixed shafts III and fixed shaft V, respectively; the water spray pipe is provided above the scrubbing roller, and one end of the water spray pipe is connected to an external water supply system through a rotating joint, including a water reservoir and a water pump; The scrubbing roller comprises a rotating shaft, an insert, a fixing plate II, a threaded rod, a roller body II, and a gear; one end of the rotating shaft is provided with a guide groove and a mounting groove and is rotatably connected to the connecting shaft through a pressure plate, the rotating shaft body is provided with a number of slots evenly distributed, a number of gears are provided and are respectively arranged in the slots and are rotatably connected to the rotating shaft through a fixing shaft; the roller body II is formed by a combination of a number of fan-shaped blocks, the fan-shaped blocks correspond to the slots, and the fan-shaped blocks are provided with ear plates; the insert is provided with a number of groups, each group is provided with a pair and symmetrically arranged in the slots, the insert is provided with a through groove, a support arm, and a rack, the rack is provided at one end of the insert and meshes with the gear, the support arm is provided in the through groove, one end of the support arm is hinged to the insert, and the other end is hinged to the ear plate; The fixing plate II is fixedly connected to one end of the inserting strip by means of bolts, the threaded rod passes through the fixing plate II, the threaded rod is connected to the fixing plate II by means of threads, and one end of the threaded rod is rotatably connected to one end of the rotating shaft.

2. The pickling process for 309S stainless steel wide hot-rolled coil according to claim 1, characterized in that In step 1), the temperature of the preheating section is controlled at 550-620°C, and the heating time is 100-120min; after the preheating section is completed, the heating section enters the first heating section, and the temperature is controlled at 950-1050°C, and the heating time is 60-70min; after the first heating section is completed, the heating section enters the second heating section, and the temperature is controlled at 1250-1270°C, and the heating time is 50-55min; after the second heating section is completed, the soaking section enters, and the temperature is controlled at 1250-1260°C, and the heating time is 40-50min; the total heating time is 255-295min.

3. The pickling process of 309S stainless steel wide hot-rolled coil according to claim 1, characterized in that In step 9), the HNO3 concentration in the first mixed acid stage is 75-80 g / L, the HF concentration is 30-40 g / L, the metal ion concentration is <40 g / L, and the temperature is 50-60°C; the HNO3 concentration in the second mixed acid stage is 50-60 g / L, the HF concentration is 30-35 g / L, the metal ion concentration is 25-45 g / L, and the temperature is 50-55°C.

4. The pickling process for 309S stainless steel wide hot-rolled coil according to claim 1, characterized in that The brushing mechanism II and the brushing mechanism I have the same structure, the brushing roller in the brushing mechanism I is arranged on one side of the stainless steel plate, and the brushing roller in the brushing mechanism II is arranged on the other side of the stainless steel plate; the flushing mechanism II and the flushing mechanism I have the same structure, the water spray pipe in the flushing mechanism I is arranged on one side of the stainless steel plate, and the water spray pipe in the flushing mechanism II is arranged on the other side of the stainless steel plate.

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