Hot continuous rolling stainless steel with good high-temperature strength and machinability and preparation method thereof

Abstract

The invention discloses hot continuous rolling stainless steel with good high-temperature strength and machinability and a preparation method of the hot continuous rolling stainless steel. The preparation method comprises the following steps: 1) smelting; 2) continuous casting; (3) coping; (4) hot rolling is conducted, specifically, the polished stainless steel is heated, and a hot coil is obtained through rough rolling, finish rolling and coiling; (5) primary annealing is conducted, specifically, the hot-rolled stainless steel enters an annealing device to be subjected to annealing treatment; a, preheating is conducted, specifically, the stainless steel enters a preheating area to be preheated; b, heating: sequentially entering a heating area I and a heating area II for heating; the turbulent flow mechanism is used for disturbing shielding gas and heat in the heating area I and the heating area II; c, heat preservation: entering a heat preservation area; d, cooling is conducted, specifically, the stainless steel enters a cooling area and is cooled through a cooling mechanism; according to the method, stainless steel can be evenly heated, defects on the surface of the stainless steel are prevented, the strength of the stainless steel is improved, the cooling efficiency of the stainless steel can be improved, and the strength of the stainless steel is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hot continuous rolling of stainless steel, and particularly relates to a hot continuous rolling stainless steel with good high-temperature strength and workability and a preparation method thereof. Background Art

[0002] In order to meet the performance of high-temperature strength and workability of stainless steel, after hot rolling, annealing treatment is carried out to improve the cutting workability of stainless steel, reduce residual stress, stabilize dimensions, reduce the tendency of deformation and cracks, refine grains, adjust the structure, and eliminate tissue defects; however, during the heating process of stainless steel in the annealing furnace, due to the uneven dispersion of heat in the annealing furnace, the stainless steel is heated unevenly, thus affecting the quality of stainless steel.

[0003] After retrieval, the prior art publication number CN113293279A discloses a structure of the outlet section of a continuous annealing furnace and a strip discharging and cooling process, including a furnace shell, furnace rolls provided in the furnace shell, and a secondary cooling section fan provided in the furnace shell; the structure of the outlet section of the annealing furnace further includes an external air cooling mechanism, and the external air cooling mechanism includes an external fan, and the air outlet of the external fan is arranged facing the strip; the following disadvantages exist in its treatment process: due to hot air around the steel strip, the efficiency of heat diffusion of the steel strip outward is low, and at the same time, the cold air blown by the fan to the steel strip first contacts the surrounding hot air, so that it cannot contact the steel strip, reducing the cooling efficiency of the steel strip.

[0004] After retrieval, the prior art publication number CN220564683U discloses a steel strip annealing furnace, including a furnace body unit having a feed port and a discharge port, the furnace body unit includes a conveying device for conveying steel plates, the conveying device includes rotating rolls rotatably assembled on the inner wall of the furnace body unit, the rotating rolls include a first rotating roll corresponding to the feed port and a second rotating roll corresponding to the discharge port, the furnace body unit further includes a heating device, and the heating device includes a main air pipe, a branch air pipe, nozzles, and an ignition member, and multiple groups of nozzles are arranged in a spiral shape between the first rotating roll and the second rotating roll; the following disadvantages exist in its treatment process: the steel plate is located in the middle of the annealing furnace, which will block the mutual flow of gases above and below the steel plate, resulting in uneven heat above and below the steel plate, further causing uneven heating of the steel plate and affecting the quality of the steel plate. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a hot continuous rolling stainless steel with good high-temperature strength and workability and a preparation method thereof. The flow disturbing mechanism can uniformly heat the stainless steel, prevent defects on the surface of the stainless steel, improve the strength of the stainless steel, and effectively reduce cracks inside the billet during casting; the cooling mechanism can reduce the hot air around the surface of the stainless steel, accelerate the flow rate of the outward diffusion of the hot air, improve the cooling efficiency of the stainless steel, and improve the strength of the stainless steel.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A hot-rolled stainless steel with good high-temperature strength and workability and a preparation method thereof, and the preparation method steps are as follows:

[0008] 1) Smelting: Smelt the stainless steel into molten stainless steel according to the chemical composition by percentage;

[0009] 2) Continuous casting: Prepare the molten steel into a stainless steel continuous casting slab with a thickness of 200 mm, and the tundish temperature is 1500 - 1520 °C;

[0010] 3) Grinding: Thermally grind the continuous casting slab through a grinding device, and the grinding temperature is 340 - 560 °C;

[0011] 4) Hot rolling: Heat the ground stainless steel continuous casting slab, the heating temperature is 1165 °C - 1215 °C, the heating time of the stainless steel continuous casting slab is 187 min - 223 min, and then obtain a hot coil through rough rolling, finish rolling, and coiling. The rough rolling temperature is 1037 °C - 1057 °C, the finish rolling temperature is 839 °C - 859 °C, and the coiling thickness is 5 mm - 6 mm;

[0012] 5) First annealing: The hot-rolled stainless steel enters an annealing device for annealing treatment: a. Preheating: First enter the preheating zone to preheat the stainless steel, and the temperature in the preheating zone is 120 - 300 °C; b. Heating: Then enter the heating zone I and heating zone II in sequence for heating. The temperature in the heating zone I is 300 °C - 500 °C; the temperature in the heating zone II is 500 - 800 °C; Perturb the protective atmosphere and heat in the heating zone I and heating zone II through a flow disturbing mechanism; The motor II in the flow disturbing mechanism provides power to drive the rotating ring to rotate along the supporting wheel through the bevel gear II, bevel gear I, connecting shaft, gear I, and tooth ring; The rotating ring drives the flow disturbing plate to rotate, so that the flow disturbing plate makes the airflows above and below the stainless steel flow mutually, further dispersing the heat and inert gas in the box body, preventing uneven heating of the stainless steel during the annealing process and causing defects on the surface of the stainless steel; c. Insulation: Then enter the insulation zone, and the temperature in the insulation zone is 790 - 810 °C, and the residence time is: 2 - 3 min; d. Cooling: Enter the cooling zone, and cool the stainless steel through a cooling mechanism; The cold air sprayed by the inclined nozzles can reduce the hot air around the surface of the stainless steel, and the cold air sprayed by the straight nozzles can directly contact the surface of the stainless steel. The inclined nozzles and straight nozzles cooperate to improve the cooling efficiency of the stainless steel; At the same time, the heat dissipation channels and heat dissipation fans can accelerate the flow rate of the hot air diffusing outward and improve the cooling efficiency of the stainless steel;

[0013] 6) Cold rolling: Perform cold rolling through a cold rolling mill;

[0014] 7) Second annealing: Anneal the cold-rolled stainless steel again;

[0015] The annealing device in Step 5 includes a box body, a feed inlet, a discharge outlet, a sealing mechanism, a flow disturbing mechanism, a cooling mechanism, transport rollers, partition board I, partition board II, an air inlet pipe, and a burner; the feed inlet and the discharge outlet are respectively located at both ends of the box body; several transport rollers are provided, and the transport rollers are rotatably connected to the side wall of the box body, and a motor I is provided at one end of the transport rollers; several partition board I are provided to divide the box body into a preheating zone, a heating zone I, a heating zone II, a heat preservation zone, and a cooling zone; partition board II is installed in the preheating zone and fixed to the side wall of the box body at the feed inlet; the sealing mechanism is installed inside partition board II; multiple groups of flow disturbing mechanisms are provided and respectively installed in the heating zone I and the heating zone II; the cooling mechanism is installed in the cooling zone; the air inlet pipe is fixed to the top of the box body and is communicated with the inside of the box body at one end; the burner is fixed to the inner side wall of the box body; the stainless steel enters the inside of the box body through the transport of the transport rollers from the feed inlet, and after passing through the sealing mechanism, the preheating zone, the heating zone I, the heating zone II, the heat preservation zone, and the cooling zone in sequence, it is discharged from the discharge outlet.

[0016] The flow disturbing mechanism includes a mounting seat I, a mounting seat II, a rotating ring, a toothed ring, a flow disturbing plate, a support plate, a connecting shaft, and a motor II; the mounting seat I is fixed to the bottom plate of the box body; a pair of mounting seat II are provided and symmetrically fixed to the inner side wall of the box body; support wheels are respectively rotatably connected to the mounting seat I and the mounting seat II; the rotating ring is installed on the support wheels, one end of the flow disturbing plate is provided with a rotating shaft, and the rotating shaft is rotatably connected to the side wall of the rotating ring through a bearing, and a counterweight is provided at the bottom of the flow disturbing plate to enable the flow disturbing plate to be in a vertical state; the toothed ring is fixed to the side wall of the rotating ring, and the support plate is fixed to the inner side wall of the box body; the connecting shaft is rotatably connected to the support plate through a bearing, and a gear I and a bevel gear I are respectively provided at both ends of the connecting shaft; the gear I is meshed with the toothed ring; the motor II is fixed to the outer side wall of the box body, and the output shaft passes through the side wall of the box body, and a bevel gear II is provided on the output shaft of the motor II, and the bevel gear II is meshed with the bevel gear I.

[0017] A stirring mechanism is provided inside the flow disturbing plate; the stirring mechanism includes a telescopic plate, an electric push rod I, a fixing plate, a connecting rod I, a connecting rod II, a moving plate, and a fan plate; an installation groove is provided on the flow disturbing plate, and the telescopic plate is installed in the installation groove; a pair of moving grooves are provided on the side wall of the flow disturbing plate; the moving grooves are communicated with the installation groove; the electric push rod I is fixed inside the flow disturbing plate on one side of the installation groove, and the output shaft is connected to the telescopic plate; the fixing plate is fixed at one end of the moving groove, and one end of the connecting rod I is rotatably connected to the fixing plate; the connecting rod II is rotatably connected to the end of the telescopic plate away from the electric push rod I; the moving plate is connected to the other ends of the connecting rod I and the connecting rod II; a pair of fan plates are provided and rotatably connected to both ends of the moving plate through a rotating shaft.

[0018] The cooling mechanism includes a cold air duct I, a cold air duct II, a heat dissipation channel, a heat exchange plate, a heat exchange tube, and a mounting plate; there are a pair of heat exchange plates symmetrically installed on the upper and lower sides of the stainless steel, the mounting plate is fixed at both ends of the heat exchange plate, the cold air duct I is rotatably connected to the mounting plate through a bearing, and an inclined nozzle is provided on the side wall of the cold air duct I; the cold air duct II is fixed on the mounting plate on one side of the cold air duct I, and a straight nozzle is provided on the cold air duct II; the cold air duct I and the cold air duct II are connected to an external cold air generator through a hose, and the cold air duct I is connected to the hose through a rotary joint; the heat exchange plate is located above the inclined nozzle, the heat exchange tube is installed inside the heat exchange plate, and a number of ventilation openings are provided on the heat exchange plate; the heat dissipation channel is fixedly connected to the heat exchange plate on one side of the straight nozzle, and a heat dissipation fan is provided on the heat dissipation channel, and one end of the heat dissipation fan is connected to a motor; the cold air enters through the cold air duct I and the cold air duct II, and then is sprayed onto the surface of the stainless steel through the inclined nozzle and the straight nozzle, so as to cool the stainless steel.

[0019] An angle adjustment mechanism is provided at one end of the cold air duct I; the angle adjustment mechanism includes a gear II, a rack, a convex block, a mounting block, and an electric push rod II; the gear II is connected to one end of the cold air duct I, a guide groove is provided at the bottom of the heat exchange plate, the rack is movably connected inside the guide groove, the rack is meshed with the gear II, the convex block is fixed on the side wall of the rack, the mounting block is installed at the bottom of the heat exchange plate, and the electric push rod II is fixed on the mounting block and the output shaft is connected to the convex block.

[0020] A lifting mechanism is connected to the heat exchange plate above the stainless steel; the lifting mechanism includes a mounting frame, a lead screw, a fixed block, a transmission shaft, a motor III, a support block, and a guide rod; the support block is fixed on the side wall of the box body, both ends of the lead screw are rotatably connected to the support block and the top plate of the box body through bearings, a bevel gear III is provided at one end of the lead screw, and the guide rod is fixed on the support block and the top plate of the box body on both sides of the lead screw; there are two groups of mounting frames, which are respectively installed on the upper and lower sides of the stainless steel; the mounting frame on the upper side of the stainless steel is threadedly connected to the lead screw, and the mounting frame on the lower side of the stainless steel is fixed on the side wall of the box body; both ends of the heat exchange plate are connected inside the corresponding mounting frame; the fixed block is fixed at the bottom of the box body, the transmission shaft is rotatably connected to the fixed block, bevel gears IV are respectively provided at both ends of the transmission shaft, and the bevel gear IV is meshed with the corresponding bevel gear III; the motor III is fixed on the top of the box body, and the output shaft is connected to the transmission shaft.

[0021] The sealing mechanism includes sealing rollers, baffles, support frames, electric push rods III, fixing frames, electric push rods IV, and air injection pipes; there are a pair of sealing rollers, which are symmetrically installed inside the box body; the support frames are rotatably connected to both ends of the sealing rollers above the stainless steel; the electric push rods III are fixed on the top of the partition II, and the output ends are connected to the support frames; the baffles are connected to the material passing openings of the partition II, the fixing frames are fixed on the outer side walls of the box body, the electric push rods IV are installed on the fixing frames, and the output ends are connected to the baffles; there are a pair of air injection pipes, which are respectively located above and below the stainless steel; the air injection pipe above the stainless steel is connected to the support frame, and the air injection pipe below the stainless steel is fixed on the side wall of the box body; the air injection pipes eject inert gas, so that the space between the partition II and the side wall of the box body is filled with inert gas, thereby isolating the external gas from the inside of the annealing furnace and preventing air from entering the annealing furnace to oxidize the stainless steel.

[0022] The beneficial effects of the present invention compared with the prior art are as follows:

[0023] 1) In the flow disturbing mechanism, the motor II provides power to drive the bevel gear II to rotate, the bevel gear II drives the bevel gear I to rotate, and the bevel gear I drives the connecting shaft and the gear I to rotate; the gear I drives the rotating ring to rotate along the support wheel through the toothed ring; the rotating ring drives the flow disturbing plate to rotate, so that the air flows above and below the stainless steel flow mutually, further dissipating the heat inside the box body, preventing uneven heating of the stainless steel caused by the fixed burner during the annealing process of the stainless steel, and causing defects on the surface of the stainless steel; at the same time, it can diffuse the protective gas inside the box body;

[0024] 2) In the stirring mechanism, the electric push rod I provides power to drive the telescopic plate to move upward, the telescopic plate drives one end of the connecting rod II to move and makes the connecting rod II rotate, the connecting rod II drives the moving plate to move, and the moving plate drives the fan plate to move; during the process of the moving plate driving the fan plate to move, the fan plate can swing around the rotating shaft, so as to disturb the local air flow, making the gas and heat inside the box body more uniform; the telescopic plate can increase the stirring area of the flow disturbing plate and improve the stirring rate; thus, the stainless steel is heated evenly, preventing defects from occurring on the surface of the stainless steel, improving the strength of the stainless steel, and effectively reducing the internal cracks of the billet during casting.

[0025] 3) Cold air enters through cold air duct I and cold air duct II, and then is ejected onto the stainless steel surface through inclined nozzles and straight nozzles, thereby cooling the stainless steel. When the inclined nozzles cool the stainless steel, the cold air ejected by the inclined nozzles blocks the hot air above the stainless steel, causing the hot air to flow upward and contact the heat exchange plate and heat exchange tubes for heat exchange. This can reduce the hot air around the stainless steel surface, facilitating subsequent cooling of the stainless steel and increasing the cooling rate of the stainless steel. At the same time, it reduces the hot air around the stainless steel that has moved behind the inclined nozzles, allowing the cold air ejected by the straight nozzles to directly contact the stainless steel surface, thereby improving the cooling efficiency of the stainless steel. The cooled gas flows outward along the heat dissipation channel under the action of the heat dissipation fan, and the heat dissipation fan can accelerate the flow rate of the hot air diffusing outward, improving the cooling efficiency of the stainless steel and enhancing the strength of the stainless steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. Figure 1 is a schematic internal structure diagram of a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0027] FIG. Figure 2 is a schematic structural diagram of the flow disturbance mechanism in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention; Figure 1 ;

[0028] FIG. Figure 3 is a schematic structural diagram of the flow disturbance mechanism in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention; Figure 2 ;

[0029] FIG. Figure 4 is a schematic structural diagram of the stirring mechanism in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0030] FIG. Figure 5 is a schematic internal structure diagram of the flow disturbance plate in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0031] FIG. Figure 6 is a schematic structural diagram of the cooling mechanism in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0032] FIG. Figure 7 is a schematic structural diagram of the heat exchange plate in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0033] FIG. Figure 8 is a schematic structural diagram of cold air duct I and cold air duct II in a hot continuous rolling stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0034] FIG. Figure 9It is an enlarged structural schematic diagram of part A in Figure 8 ;

[0035] Attached Figure 10 is a structural schematic diagram of the sealing mechanism in a hot-rolled stainless steel with good high-temperature strength and workability and its preparation method according to the present invention;

[0036] Attached Figure 11 is a structural schematic of a hot-rolled stainless steel with good high-temperature strength and workability and its preparation method according to the present invention Figure 1 ;

[0037] Attached Figure 12 is a structural schematic of a hot-rolled stainless steel with good high-temperature strength and workability and its preparation method according to the present invention Figure 2 ;

[0038] In the figure: 1. Box body; 2. Feed inlet; 3. Discharge outlet; 4. Sealing mechanism; 401. Sealing roller; 402. Baffle; 403. Support frame; 404. Electric push rod III; 405. Fixed frame; 406. Electric push rod IV; 407. Air spraying pipe; 5. Turbulence mechanism; 501. Mounting seat I; 5011. Support wheel; 502. Mounting seat II; 503. Rotating ring; 504. Tooth ring; 505. Turbulence plate; 5051. Rotating shaft; 5052. Installation groove; 5053. Moving groove; 5054. Counterweight; 506. Support plate; 507. Connecting shaft; 5071. Gear I; 5072. Bevel gear I; 508. Motor II; 5081. Bevel gear II; 509. Stirring mechanism; 5091. Telescopic plate; 5092. Electric push rod I; 5093. Fixed plate; 5094. Connecting rod I; 5095. Connecting rod II; 5096. Moving plate; 5097. Fan plate; 6. Cooling mechanism; 601. Cold air pipe I; 6011. Oblique nozzle; 602. Cold air pipe II; 6021. Straight nozzle; 603. Heat dissipation channel; 6031. Heat dissipation fan; 604. Heat exchange plate; 6041. Ventilation opening; 6042. Guide groove; 605. Heat exchange tube; 606. Mounting plate; 607. Angle adjustment mechanism; 6071. Gear II; 6072. Rack; 6073. Convex block; 6074. Mounting block; 6075. Electric push rod II; 608. Lifting mechanism; 6081. Mounting frame; 6082. Lead screw; 60821. Bevel gear III; 6083. Fixed block; 6084. Transmission shaft; 60841. Bevel gear IV; 6085. Motor III; 6086. Support block; 6087. Guide rod; 7. Conveyor roller; 701. Motor I; 8. Partition I; 9. Partition II; 11. Inlet pipe; 12. Burner; 13. Stainless steel. Detailed implementation manners

[0039] For the convenience of those skilled in the art to understand, the following is combined with the attached Figure 1-12, to further specifically describe the technical solution of the present invention.

[0040] Example 1:

[0041] A hot-rolled stainless steel with good high-temperature strength and workability and its preparation method. The steps of the preparation method are as follows:

[0042] 1) Smelting: Smelt stainless steel molten steel according to the chemical composition by percentage.

[0043] 2) Continuous casting: Prepare the molten steel into a stainless steel continuous casting slab with a thickness of 200 mm.

[0044] 3) Grinding: Thermally grind the continuous casting slab through a grinding device, and the grinding temperature is 340 °C.

[0045] 4) Hot rolling: Heat the ground stainless steel continuous casting slab, the heating temperature is 1165 °C, the heating time of the stainless steel continuous casting slab is 187 min, and then obtain a hot coil through rough rolling, finish rolling, and coiling. The rough rolling temperature is 1037 °C, the finish rolling temperature is 839 °C, and the coiling thickness is 5 mm.

[0046] 5) First annealing: The hot-rolled stainless steel enters the annealing device for annealing treatment: a. Preheating: First enter the preheating zone to preheat the stainless steel, and the temperature in the preheating zone is 120 °C; b. Heating: Then enter the heating zone I and heating zone II in sequence for heating. The temperature of heating zone I is 300 °C; the temperature of heating zone II is 500 °C; The protective atmosphere and heat in heating zone I and heating zone II are disturbed through a turbulence mechanism, so as to uniformly heat the stainless steel and prevent defects on the surface of the stainless steel; c. Insulation: Then enter the insulation zone, the temperature in the insulation zone is 790 °C, and the residence time is: 2 min; d. Cooling: Enter the cooling zone, and cool the stainless steel through a cooling mechanism; The cold air sprayed by the inclined nozzle can reduce the hot air around the surface of the stainless steel, and the cold air sprayed by the straight nozzle can directly contact the surface of the stainless steel. The inclined nozzle and the straight nozzle cooperate to improve the cooling efficiency of the stainless steel; At the same time, the heat dissipation channel and the heat dissipation fan can accelerate the flow rate of the hot air diffusing outward and improve the cooling efficiency of the stainless steel.

[0047] 6) Cold rolling: Cold roll through a cold rolling mill.

[0048] 7) Second annealing: Anneal the cold-rolled stainless steel again.

[0049] The annealing device in step 5 includes a box body 1, a feed inlet 2, a discharge outlet 3, a sealing mechanism 4, a flow disturbing mechanism 5, a cooling mechanism 6, a conveying roller 7, a partition board I 8, a partition board II 9, an air inlet pipe 11, and a burner 12. The feed inlet 2 and the discharge outlet 3 are respectively located at both ends of the box body 1. There are several conveying rollers 7, and the conveying rollers 7 are rotatably connected to the side wall of the box body 1. One end of the conveying roller 7 is provided with a motor I 701. There are several partition boards I 8 that divide the box body 1 into a preheating zone, a heating zone I, a heating zone II, a heat preservation zone, and a cooling zone. The partition board II 9 is installed in the preheating zone and is fixed to the side wall of the box body 1 at the feed inlet 2. The sealing mechanism 4 is installed inside the partition board II 9. There are multiple groups of flow disturbing mechanisms 5, which are respectively installed in the heating zone I and the heating zone II. The cooling mechanism 6 is installed in the cooling zone. The air inlet pipe 11 is fixed to the top of the box body 1 and is communicated with the inside of the box body 1 at one end. The burner 12 is fixed to the inner side wall of the box body 1. The stainless steel 13 enters the inside of the box body 1 through the feed inlet 2 by the transportation of the conveying roller 7. The stainless steel 13 sequentially passes through the sealing mechanism, the preheating zone, the heating zone I, the heating zone II, the heat preservation zone, and the cooling zone, and then is discharged from the discharge outlet 3.

[0050] The flow disturbing mechanism 5 includes a mounting seat I 501, a mounting seat II 502, a rotating ring 503, a toothed ring 504, a flow disturbing plate 505, a support plate 506, a connecting shaft 507, and a motor II 508. The mounting seat I 501 is fixed to the bottom plate of the box body 1. There are a pair of mounting seats II 502, which are symmetrically fixed to the inner side wall of the box body 1. Support wheels 5011 are respectively rotatably connected to the mounting seat I 501 and the mounting seat II 502. The rotating ring 503 is installed on the support wheels 5011. One end of the flow disturbing plate 505 is provided with a rotating shaft 5051, and the rotating shaft 5051 is rotatably connected to the side wall of the rotating ring 503 through a bearing. A counterweight 5054 is provided at the bottom of the flow disturbing plate 505, and the counterweight 5054 can make the flow disturbing plate in a vertical state. The toothed ring 504 is fixed to the side wall of the rotating ring 503. The support plate 506 is fixed to the inner side wall of the box body 1. The connecting shaft 507 is rotatably connected to the support plate 506 through a bearing. A gear I 5071 and a bevel gear I 5072 are respectively provided at both ends of the connecting shaft 507. The gear I 5071 is meshed and connected with the toothed ring 504. The motor II 508 is fixed to the outer side wall of the box body 1, and the output shaft passes through the side wall of the box body 1. A bevel gear II 5081 is provided on the output shaft of the motor II 508, and the bevel gear II 5081 is meshed and connected with the bevel gear I 5072.

[0051] The motor II 508 provides power to drive the bevel gear II 5081 to rotate. The bevel gear II 5081 drives the bevel gear I 5072 to rotate, and the bevel gear I 5072 drives the connecting shaft 507 and the gear I 5071 to rotate. The gear I 5071 drives the rotating ring 503 to rotate along the support wheel 5011 through the tooth ring 504. The rotating ring 503 drives the spoiler 505 to rotate, so that the air flow above and below the stainless steel 13 flows mutually, further dissipating the heat in the box body 1, preventing uneven heating of the stainless steel 13 during the annealing process of the stainless steel 13 due to the fixation of the burner 12, and causing defects on the surface of the stainless steel 13. At the same time, it can diffuse the protective gas inside the box body 1.

[0052] A stirring mechanism 509 is arranged inside the spoiler 505. The stirring mechanism 509 includes a telescopic plate 5091, an electric push rod I 5092, a fixing plate 5093, a connecting rod I 5094, a connecting rod II 5095, a moving plate 5096, and a fan plate 5097. An installation groove 5052 is provided on the spoiler 505, and the telescopic plate 5091 is installed in the installation groove 5052. A pair of moving grooves 5053 are provided on the side wall of the spoiler 505. The moving grooves 5053 communicate with the installation groove 5052. The electric push rod I 5092 is fixed inside the spoiler 505 on one side of the installation groove 5052, and the output shaft is connected to the telescopic plate 5091. The fixing plate 5093 is fixed at one end of the moving groove 5053, and one end of the connecting rod I 5094 is rotatably connected to the fixing plate 5093. The connecting rod II 5095 is rotatably connected to the end of the telescopic plate 5091 away from the electric push rod I 5092. The moving plate 5096 is connected to the other ends of the connecting rod I 5094 and the connecting rod II 5095. A pair of fan plates 5097 are provided and are rotatably connected to both ends of the moving plate 5096 through a rotating shaft.

[0053] The electric push rod I 5092 provides power to drive the telescopic plate 5091 to move upward. The telescopic plate 5091 drives one end of the connecting rod II 5095 to move, causing the connecting rod II 5095 to rotate. The connecting rod II 5095 drives the moving plate 5096 to move, and the moving plate 5096 drives the fan plate 5097 to move. During the process of the moving plate 5096 driving the fan plate 5097 to move, the fan plate 5097 can swing around the rotating shaft, thereby disturbing the local air flow and making the gas and heat in the box body 1 more uniform. The telescopic plate 5091 can increase the stirring area of the spoiler and improve the stirring rate. Thus, the stainless steel is heated evenly, preventing defects from occurring on the surface of the stainless steel.

[0054] The cooling mechanism 6 includes a cold air duct I 601, a cold air duct II 602, a heat dissipation channel 603, a heat exchange plate 604, a heat exchange tube 605, and a mounting plate 606; there are a pair of heat exchange plates 604 symmetrically installed on the upper and lower sides of the stainless steel 13, the mounting plate 606 is fixed at both ends of the heat exchange plate 604, the cold air duct I 601 is rotatably connected to the mounting plate 606 through a bearing, and an inclined nozzle 6011 is provided on the side wall of the cold air duct I 601; the cold air duct II 602 is fixed on the mounting plate 606 on one side of the cold air duct I 601, and a straight nozzle 6021 is provided on the cold air duct II 602; the cold air duct I 601 and the cold air duct II 602 are connected to an external cold air generator through a hose, and the cold air duct I 601 is connected to the hose through a rotary joint; the heat exchange plate 604 is located above the inclined nozzle 6011, the heat exchange tube 605 is installed inside the heat exchange plate 604, and a number of ventilation openings 6041 are provided on the heat exchange plate 604; the heat dissipation channel 603 is fixedly connected to the heat exchange plate 604 on one side of the straight nozzle 6021, and a heat dissipation fan 6031 is provided on the heat dissipation channel 603; one end of the heat dissipation fan 6031 is connected to a motor; the cold air enters through the cold air duct I 601 and the cold air duct II 602, and then is sprayed onto the surface of the stainless steel 13 through the inclined nozzle 6011 and the straight nozzle 6021, thereby cooling the stainless steel 13.

[0055] When the inclined nozzle 6011 cools the stainless steel 13, the cold air sprayed by the inclined nozzle 6011 blocks the hot air above the stainless steel 13, causing the hot air to flow upward and contact the heat exchange plate 604 and the heat exchange tube 605 for heat exchange, thereby reducing the hot air around the surface of the stainless steel 13, facilitating subsequent cooling of the stainless steel 13, and improving the cooling rate of the stainless steel 13; at the same time, the hot air around the stainless steel 13 moving behind the inclined nozzle 6011 is reduced, and the cold air sprayed by the straight nozzle 6021 can directly contact the surface of the stainless steel 13, thereby improving the cooling efficiency of the stainless steel 13; the cooled gas flows outward along the heat dissipation channel 603 under the action of the heat dissipation fan 6031, and the heat dissipation fan 6031 can accelerate the flow rate of the hot air diffusing outward, improving the cooling efficiency of the stainless steel 13.

[0056] One end of the cold air duct I 601 is provided with an angle adjustment mechanism 607; the angle adjustment mechanism 607 includes a gear II 6071, a rack 6072, a convex block 6073, a mounting block 6074, and an electric push rod II 6075; the gear II 6071 is connected to one end of the cold air duct I 601, a guide groove 6042 is provided at the bottom of the heat exchange plate 604, the rack 6072 is movably connected inside the guide groove 6042, the rack 6072 is meshed with the gear II 6071, the convex block 6073 is fixed on the side wall of the rack 6072, the mounting block 6074 is installed at the bottom of the heat exchange plate 604, and the electric push rod II 6075 is fixed on the mounting block 6074 and its output shaft is connected to the convex block 6073.

[0057] The electric push rod II 6075 provides power to drive the bump 6073 to move, and the bump 6073 drives the rack 6072 to move along the guide groove 6042; the rack 6072 drives the cold air duct I 601 to rotate through the gear II 6071, so as to adjust the spraying angle of the inclined nozzle 6011; thus, it can adapt to stainless steel 13 with different thicknesses.

[0058] A lifting mechanism 608 is connected to the heat exchange plate 604 above the stainless steel 13; the lifting mechanism 608 includes a mounting frame 6081, a lead screw 6082, a fixed block 6083, a transmission shaft 6084, a motor III 6085, a support block 6086, and a guide rod 6087; the support block 6086 is fixed on the side wall of the box body 1, and the two ends of the lead screw 6082 are rotationally connected to the support block 6086 and the top plate of the box body 1 through bearings. A bevel gear III 60821 is provided at one end of the lead screw 6082, and the guide rod 6087 is fixed on the support block 6086 and the top plate of the box body 1 on both sides of the lead screw 6082; there are two groups of mounting frames 6081, which are respectively installed on the upper and lower sides of the stainless steel 13; the mounting frame 6081 on the upper side of the stainless steel 13 is threadedly connected to the lead screw 6082, and the mounting frame 6081 on the lower side of the stainless steel 13 is fixed on the side wall of the box body 1; both ends of the heat exchange plate 604 are connected to the inside of the corresponding mounting frame 6081; the fixed block 6083 is fixed on the bottom of the box body 1, the transmission shaft 6084 is rotationally connected to the fixed block 6083, and bevel gears IV 60841 are respectively provided at both ends of the transmission shaft 6084, and the bevel gear IV 60841 is meshed and connected to the corresponding bevel gear III 60821; the motor III 6085 is fixed on the top of the box body 1, and the output shaft is connected to the transmission shaft 6084;

[0059] The motor III 6085 provides power to drive the transmission shaft 6084 to rotate. The transmission shaft 6084 drives the lead screw 6082 to rotate through the bevel gear IV 60841 and the bevel gear III 60821. The lead screw 6082 drives the mounting frame 6081 to move along the guide rod 6087 through the thread; the mounting frame 6081 drives the cooling mechanism 6 to move, so as to adjust the distance between the cold air duct I 601 and the cold air duct II 602 and the surface of the stainless steel 13, and further adapt to stainless steel 13 with different thicknesses.

[0060] The sealing mechanism 4 includes a sealing roller 401, a baffle 402, a support frame 403, an electric push rod III 404, a fixing frame 405, an electric push rod IV 406, and a gas spraying pipe 407. There are a pair of sealing rollers 401, which are symmetrically installed inside the box body 1. The support frame 403 is rotatably connected to both ends of the sealing roller 401 above the stainless steel 13. The electric push rod III 404 is fixed on the top of the partition II 9, and its output end is connected to the support frame 403. The baffle 402 is connected to the material passing opening of the partition II 9. The fixing frame 405 is fixed on the outer side wall of the box body 1. The electric push rod IV 406 is installed on the fixing frame 405, and its output end is connected to the baffle 402. There are a pair of gas spraying pipes 407, which are respectively located above and below the stainless steel 13. The gas spraying pipe 407 above the stainless steel 13 is connected to the support frame 403, and the gas spraying pipe 407 below the stainless steel 13 is fixed on the side wall of the box body 1. The gas spraying pipe 407 sprays inert gas, so that the space between the partition II 9 and the side wall of the box body 1 is filled with inert gas, thereby isolating the external gas from the inside of the annealing furnace and preventing air from entering the annealing furnace to oxidize the stainless steel 13.

[0061] Example 2: The difference from Example 1 is as follows;

[0062] 3) Grinding: The continuous casting slab is thermally ground by a grinding device, and the grinding temperature is 410 °C;

[0063] 4) Hot rolling: The ground stainless steel continuous casting slab is heated, the heating temperature is 1190 °C, the heating time of the stainless steel continuous casting slab is 200 min, and then a hot coil is obtained through rough rolling, finish rolling, and coiling. The rough rolling temperature is 1043 °C, the finish rolling temperature is 849 °C, and the coiling thickness is 5.5 mm;

[0064] 5) First annealing: The hot-rolled stainless steel enters the annealing device for annealing treatment: a. Preheating: First, it enters the preheating zone to preheat the stainless steel, and the temperature in the preheating zone is 200 °C; b. Heating: Then it enters the heating zone I and heating zone II in sequence for heating. The temperature in the heating zone I is 400 °C; the temperature in the heating zone II is 650 °C; the turbulence mechanism disturbs the protective atmosphere and heat in the heating zone I and heating zone II, so as to uniformly heat the stainless steel and prevent defects on the surface of the stainless steel; c. Heat preservation: Then it enters the heat preservation zone, the temperature in the heat preservation zone is 800 °C, and the residence time is: 2.5 min; d. Cooling: It enters the cooling zone, and the stainless steel is cooled by the cooling mechanism; the cold air sprayed by the inclined nozzle can reduce the hot air around the surface of the stainless steel, and the cold air sprayed by the straight nozzle can directly contact the surface of the stainless steel. The inclined nozzle and the straight nozzle cooperate to improve the cooling efficiency of the stainless steel; at the same time, the heat dissipation channels and heat dissipation fans can accelerate the flow rate of the hot air diffusing outward and improve the cooling efficiency of the stainless steel.

[0065] Example 3: The difference from Example 1 is as follows;

[0066] 3) Grinding: The continuous casting slab is hot ground by a grinding device, and the grinding temperature is 560°C;

[0067] 4) The ground stainless steel continuous casting slab is heated. The heating temperature is 1215°C, and the heating time of the stainless steel continuous casting slab is 223 min. Then, hot coils are obtained through rough rolling, finish rolling, and coiling. The rough rolling temperature is 1057°C, the finish rolling temperature is 859°C, and the coiling thickness is 6 mm;

[0068] 5) First annealing: The hot-rolled stainless steel enters the annealing device for annealing treatment: a. Preheating: First, it enters the preheating zone to preheat the stainless steel, and the temperature in the preheating zone is 300°C; b. Heating: Then, it enters the heating zone I and heating zone II in sequence for heating. The temperature in heating zone I is 500°C; the temperature in heating zone II is 800°C; The protective atmosphere and heat in heating zone I and heating zone II are disturbed by a flow disturbing mechanism, so as to uniformly heat the stainless steel and prevent defects from occurring on the surface of the stainless steel; c. Insulation: Then, it enters the insulation zone, and the temperature in the insulation zone is 810°C, and the residence time is: 3 min; d. Cooling: It enters the cooling zone, and the stainless steel is cooled by a cooling mechanism; The cold air sprayed by the inclined nozzles can reduce the hot air around the surface of the stainless steel, and the cold air sprayed by the straight nozzles can directly contact the surface of the stainless steel. The inclined nozzles and straight nozzles cooperate to improve the cooling efficiency of the stainless steel; At the same time, the heat dissipation channels and heat dissipation fans can accelerate the flow rate of the hot air diffusing outwards and improve the cooling efficiency of the stainless steel.

[0069] Comparative example: The stainless steel rolled by any of the hot rolling processes in Examples 1-3, and then the stainless steel produced by using the ferritic stainless steel with good high-temperature strength and workability and its preparation method with the patent number CN119220882A.

[0070] Surface inspection results of Example 1, Example 2, and Example 3; The surface of the plate is clean, without obvious scratches, indentations, color differences and other defects; There are no cracks or peeling on the surface; At the same time, the hot surface quality of the rolled stainless steel is good, and the edges are neat without curling; Moreover, for the stainless steel strength, the internal cracks of the casting blank are effectively reduced during casting, and at the same time, the yield strength and tensile strength of the stainless steel are improved.

[0071] Surface inspection results of the comparative example: There are no obvious scratches, indentations, pits and other defects on the plate surface; There is a situation where the surface is locally dark-spotted.

[0072] According to the above conclusions, it can be known that among the inspection results of the above-mentioned examples and comparative examples, the surface quality of the stainless steel in Examples 1-3 is the best, for the stainless steel strength, and there are different degrees of surface darkening on the plate surface of the comparative example.

[0073] The above is only an example and explanation of the structure of the present invention. Those skilled in the art of this technology can make various modifications, supplements or use similar methods to replace the specific embodiments described. As long as it does not deviate from the structure of the invention or exceed the scope defined by this claim book, it shall fall within the protection scope of the present invention.

Claims

1. A hot-rolled stainless steel with good high-temperature strength and workability and a preparation method thereof, characterized in that The preparation method steps are as follows: 1) Smelting: The stainless steel is smelted into molten stainless steel according to the percentage of chemical components; 2) Continuous casting: The molten steel is made into a stainless steel continuous casting slab with a thickness of 200 mm, and the tundish temperature is 1500 - 1520 °C; 3) Grinding: The continuous casting slab is hot ground by a grinding device, and the grinding temperature is 340 - 560 °C; 4) Hot rolling: The ground stainless steel continuous casting slab is heated, the heating temperature is 1165 °C - 1215 °C, the heating time of the stainless steel continuous casting slab is 187 min - 223 min, and then a hot coil is obtained through rough rolling, finish rolling, and coiling. The rough rolling temperature is 1037 °C - 1057 °C, the finish rolling temperature is 839 °C - 859 °C, and the coiling thickness is 5 mm - 6 mm; 5) First annealing: The hot-rolled stainless steel enters the annealing device for annealing treatment: a. Preheating: First, it enters the preheating zone to preheat the stainless steel, and the temperature in the preheating zone is 120 - 300 °C; b. Heating: Then it enters the heating zone I and heating zone II in sequence for heating. The temperature in the heating zone I is 300 °C - 500 °C; the temperature in the heating zone II is 500 - 800 °C; the protective atmosphere and heat in the heating zone I and heating zone II are disturbed by a turbulence mechanism. The motor II in the turbulence mechanism provides power to drive the rotating ring to rotate along the support wheel through bevel gear II, bevel gear I, connecting shaft, gear I, and tooth ring; the rotating ring drives the turbulence plate to rotate, so that the airflows above and below the stainless steel flow mutually, further dispersing the heat and inert gas in the box body, preventing uneven heating of the stainless steel during annealing and causing defects on the stainless steel surface; c. Insulation: Then it enters the insulation zone, and the temperature in the insulation zone is 790 - 810 °C, and the residence time is: 2 - 3 min; d. Cooling: It enters the cooling zone, and the stainless steel is cooled by a cooling mechanism; the cold air sprayed by the inclined nozzles can reduce the hot air around the stainless steel surface, and the cold air sprayed by the straight nozzles can directly contact the stainless steel surface. The inclined nozzles and straight nozzles cooperate to improve the cooling efficiency of the stainless steel; at the same time, the heat dissipation channels and heat dissipation fans can accelerate the flow rate of the hot air diffusing outward and improve the cooling efficiency of the stainless steel; 6) Cold rolling: Cold rolling is carried out by a cold rolling mill; 7) Second annealing: The cold-rolled stainless steel is annealed again; The annealing device in step 5 includes a box body, a feed inlet, a discharge outlet, a sealing mechanism, a turbulence mechanism, a cooling mechanism, a conveying roller, a partition I, a partition II, an air inlet pipe, and a burner; the feed inlet and the discharge outlet are respectively located at both ends of the box body; several conveying rollers are provided, and the conveying rollers are rotatably connected to the side wall of the box body, and a motor I is provided at one end of the conveying roller; several partition I are provided to divide the box body into a preheating zone, a heating zone I, a heating zone II, an insulation zone, and a cooling zone; the partition II is installed in the preheating zone and fixed on the side wall of the box body at the feed inlet; the sealing mechanism is installed inside the partition II; multiple groups of turbulence mechanisms are provided and installed in the heating zone I and heating zone II respectively; the cooling mechanism is installed in the cooling zone; the air inlet pipe is fixed on the top of the box body and one end is communicated with the inside of the box body; the burner is fixed on the inner side wall of the box body.

2. The hot-rolled stainless steel with good high-temperature strength and workability according to claim 1 and its preparation method are characterized in that The spoiler mechanism includes mounting base Ⅰ, mounting base Ⅱ, swivel ring, toothed ring, spoiler, support plate, connecting shaft, and motor Ⅱ; mounting base Ⅰ is fixed on the bottom plate of the box body; there are a pair of mounting bases Ⅱ, which are symmetrically fixed on the inner side wall of the box body; support wheels are respectively rotatably connected to mounting base Ⅰ and mounting base Ⅱ; the swivel ring is mounted on the support wheels, one end of the spoiler is provided with a rotating shaft, and the rotating shaft is rotatably connected to the side wall of the swivel ring through a bearing, and a counterweight is provided at the bottom of the spoiler; the toothed ring is fixed on the side wall of the swivel ring, and the support plate is fixed on the inner side wall of the box body; the connecting shaft is rotatably connected to the support plate through a bearing, and a gear Ⅰ and a bevel gear Ⅰ are respectively provided at both ends of the connecting shaft; gear Ⅰ is meshed with the toothed ring; motor Ⅱ is fixed on the outer side wall of the box body, and the output shaft passes through the side wall of the box body. A bevel gear Ⅱ is provided on the output shaft of motor Ⅱ, and bevel gear Ⅱ is meshed with bevel gear Ⅰ.

3. A hot-rolled stainless steel with good high-temperature strength and workability and a preparation method thereof according to claim 2, characterized in that A stirring mechanism is provided inside the spoiler; the stirring mechanism includes a telescopic plate, electric push rod Ⅰ, fixed plate, connecting rod Ⅰ, connecting rod Ⅱ, moving plate, and fan plate; an installation groove is provided on the spoiler, and the telescopic plate is installed in the installation groove; a pair of moving grooves are provided on the side wall of the spoiler; the moving grooves communicate with the installation groove; electric push rod Ⅰ is fixed inside the spoiler on one side of the installation groove, and the output shaft is connected to the telescopic plate; the fixed plate is fixed at one end of the moving groove, and one end of connecting rod Ⅰ is rotatably connected to the fixed plate; connecting rod Ⅱ is rotatably connected to the end of the telescopic plate away from electric push rod Ⅰ; the moving plate is connected to the other ends of connecting rod Ⅰ and connecting rod Ⅱ; there are a pair of fan plates, which are rotatably connected to both ends of the moving plate through a rotating shaft.

4. A hot-rolled stainless steel with good high-temperature strength and processability and a preparation method thereof according to claim 1, characterized in that The cooling mechanism includes cold air duct Ⅰ, cold air duct Ⅱ, heat dissipation channel, heat exchange plate, heat exchange tube, and mounting plate; there are a pair of heat exchange plates, which are symmetrically installed on the upper and lower sides of the stainless steel. The mounting plate is fixed at both ends of the heat exchange plate. Cold air duct Ⅰ is rotatably connected to the mounting plate through a bearing, and an inclined nozzle is provided on the side wall of cold air duct Ⅰ; cold air duct Ⅱ is fixed on the mounting plate on one side of cold air duct Ⅰ, and a straight nozzle is provided on cold air duct Ⅱ; cold air duct Ⅰ and cold air duct Ⅱ are connected to an external cold air generator through a hose. Cold air duct Ⅰ is connected to the hose through a rotary joint; the heat exchange plate is located above the inclined nozzle, the heat exchange tube is installed inside the heat exchange plate, and several ventilation openings are provided on the heat exchange plate; the heat dissipation channel is fixedly connected to the heat exchange plate on one side of the straight nozzle, and a heat dissipation fan is provided on the heat dissipation channel. One end of the heat dissipation fan is connected to a motor.

5. A hot-rolled stainless steel with good high-temperature strength and workability and a preparation method thereof according to claim 1, characterized in that An angle adjustment mechanism is provided at one end of cold air duct Ⅰ; the angle adjustment mechanism includes gear Ⅱ, rack, convex block, mounting block, and electric push rod Ⅱ; gear Ⅱ is connected to one end of cold air duct Ⅰ, a guide groove is provided at the bottom of the heat exchange plate, the rack is movably connected inside the guide groove, the rack is meshed with gear Ⅱ, the convex block is fixed on the side wall of the rack, the mounting block is installed at the bottom of the heat exchange plate, and electric push rod Ⅱ is fixed on the mounting block, and the output shaft is connected to the convex block.

6. The hot-rolled stainless steel with good high-temperature strength and processability according to claim 1 and its preparation method are characterized in that A lifting mechanism is connected to the heat exchange plate above the stainless steel. The lifting mechanism includes a mounting frame, a lead screw, a fixed block, a transmission shaft, a motor III, a support block, and a guide rod. The support block is fixed on the side wall of the box body. The two ends of the lead screw are rotatably connected to the support block and the top plate of the box body through bearings. A bevel gear III is provided at one end of the lead screw. The guide rod is fixed on the support block and the top plate of the box body on both sides of the lead screw. There are two groups of mounting frames, which are respectively installed on the upper and lower sides of the stainless steel. The mounting frame on the upper side of the stainless steel is threadedly connected to the lead screw, and the mounting frame on the lower side of the stainless steel is fixed on the side wall of the box body. Both ends of the heat exchange plate are connected to the inside of the corresponding mounting frame. The fixed block is fixed at the bottom of the box body. The transmission shaft is rotatably connected to the fixed block. Bevel gears IV are respectively provided at both ends of the transmission shaft, and the bevel gears IV are meshed and connected to the corresponding bevel gears III. The motor III is fixed on the top of the box body, and the output shaft is connected to the transmission shaft.

7. A hot-rolled stainless steel with good high-temperature strength and processability and a preparation method thereof according to claim 1, characterized in that The sealing mechanism includes sealing rollers, baffles, support frames, electric push rods III, fixed frames, electric push rods IV, and air spray pipes. There is a pair of sealing rollers, which are symmetrically installed inside the box body. The support frames are rotatably connected to both ends of the sealing rollers above the stainless steel. The electric push rod III is fixed on the top of the partition II, and the output end is connected to the support frame. The baffle is connected to the material passing port of the partition II. The fixed frame is fixed on the outer side wall of the box body. The electric push rod IV is installed on the fixed frame, and the output end is connected to the baffle. There is a pair of air spray pipes, which are respectively located above and below the stainless steel. The air spray pipe above the stainless steel is connected to the support frame, and the air spray pipe below the stainless steel is fixed on the side wall of the box body.

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