CN112143877B

CN112143877B - Full-continuous heat treatment production system and method for hot-rolled high-strength steel

Info

Publication number: CN112143877B
Application number: CN202010909183.4A
Authority: CN
Inventors: 许立雄; 廖砚林; 马瑞杰; 李卫杰; 梁芳; 况群意; 何涛
Original assignee: Wisdri Engineering and Research Incorporation Ltd
Current assignee: Wisdri Engineering and Research Incorporation Ltd
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2024-02-23
Anticipated expiration: 2040-09-02
Also published as: CN112143877A

Abstract

The invention relates to a hot-rolled high-strength steel full-continuous heat treatment production system and a hot-rolled high-strength steel heat treatment method based on the hot-rolled high-strength steel full-continuous heat treatment production system. The invention can realize the full continuous heat treatment production of the hot-rolled high-strength steel, obviously improve the heat treatment production efficiency of the hot-rolled high-strength steel, shorten the process flow, save the investment and reduce the operation energy consumption.

Description

Full-continuous heat treatment production system and method for hot-rolled high-strength steel

Technical Field

The invention belongs to the technical field of high-strength steel production, and relates to a hot-rolled high-strength steel full-continuous heat treatment production system and a hot-rolled high-strength steel heat treatment method based on the hot-rolled high-strength steel full-continuous heat treatment production system.

Background

Along with the development of the steel industry to the green and intelligent directions and the improvement of the modern industrial level, the industries of engineering machinery, commercial vehicles and the like bring urgent demands to the aspects of light structure, product upgrading and updating, product service life improvement and the like of steel materials, and the high-strength steel presents huge market space. For the engineering machinery industry, the strength level of steel is improved, a large amount of energy cost can be saved, and the safety performance of engineering machinery is improved; for the commercial vehicle industry, the strength is improved, the weight of the vehicle can be reduced, the energy conservation and emission reduction are realized, and the service life is prolonged. In recent years, part of heavy industry manufacturers begin to adopt super-high strength structural steel with the pressure of 960MPa or more to manufacture crane boom and pump truck distributing rod; partial dumper users intentionally adopt HB400-500 grade thin wear-resisting plates to replace commonly used 345MPa grade products; the truck industry has a potential need for reducing the weight of girders using ultra-high strength steel. It can be seen that the future iron and steel market has put higher and higher demands on the quality and yield of high-strength steel.

The early high-strength steel is developed by adopting an alloying method, namely, the carbon content and the alloy content in the steel are increased, and the strength of the steel is improved through solid solution strengthening, precipitation strengthening and phase change strengthening, but the alloy cost of the method is too high, and the welding performance and the plastic toughness of the steel are poor. In recent years, the production of high-strength steel by TMCP technology has become the mainstream, namely, the high-strength steel with good toughness matching is obtained by combining on-line controlled rolling and controlled cooling; however, the TMCP technology has longer technological process and poorer temperature uniformity of the steel plate, so that the fluctuation of the mechanical properties of the product is larger. In addition, for hot rolled coils, the high-strength steel produced by on-line rapid cooling is limited by coiling, uncoiling and straightening capabilities, and the production difficulty is high. In contrast, the heat treatment production process of the hot rolled coil has obvious advantages for producing high-strength steel products with uniform performance.

The main heat treatment production processes of the high-strength steel in China at present mainly comprise an off-line tempering (FQT) process and a direct quenching and off-line tempering (DQT) process. Patent CN101831530a discloses a heat treatment process for improving comprehensive mechanical properties of low alloy high strength steel, the method refines the martensitic structure through 3-6 times of cyclic quenching and tempering processes, thereby improving the strength of the steel, but the method needs multiple times of heating and cooling, and has large energy consumption and long production period. Patent CN106148822a proposes a method for producing a high-strength steel Q890 medium plate, which obtains a product with qualified performance through online quenching and offline high-temperature tempering, and shortens the process flow at the same time, but the temperature uniformity in the hot rolling and quenching processes is difficult to control, so that the performance fluctuation of the final product is larger.

Disclosure of Invention

The invention relates to a hot-rolled high-strength steel full-continuous heat treatment production system and a hot-rolled high-strength steel heat treatment method based on the hot-rolled high-strength steel full-continuous heat treatment production system, which at least can solve part of defects in the prior art.

The invention relates to a full-continuous heat treatment production system for hot-rolled high-strength steel, which comprises an uncoiler, a welding machine, a quenching device, a tempering device, a slitting shear and a product collecting unit which are sequentially connected in the running direction of the steel, wherein the quenching device comprises a quenching heating section and a quenching cooling section which are sequentially arranged in the running direction of the steel, and the tempering device comprises a tempering heating section and a tempering cooling section which are sequentially arranged in the running direction of the steel.

As one embodiment, the quenching heating section comprises a first longitudinal magnetic induction heating furnace section, a transverse magnetic induction heating furnace section and a first soaking furnace section which are sequentially arranged along the running direction of the steel.

As one embodiment, the quenching heating section further comprises a first side heating furnace section, the first side heating furnace section is arranged between the transverse magnetic induction heating furnace section and the first soaking furnace section, the first side heating furnace section comprises two groups of first side heating mechanisms for heating the side parts of the strip steel, and the two groups of first side heating mechanisms are arranged on the transmission side and the operation side of the furnace body.

As one of implementation modes, the quenching cooling section comprises a plurality of cooling boxes which are sequentially arranged along the running direction of the strip steel, an intermediate tension roller is arranged between two adjacent cooling boxes, a cooling mechanism is arranged in each cooling box, and the cooling mechanism comprises an aerosol cooling mechanism and/or a water spray cooling mechanism.

As one embodiment, the tempering heating section comprises a second longitudinal magnetic induction heating furnace section and a second soaking furnace section which are sequentially arranged along the running direction of the strip steel.

As one of the implementation manners, the tempering heating section further comprises a second side heating furnace section, the second side heating furnace section is arranged between the second longitudinal magnetic induction heating furnace section and the second soaking furnace section, the second side heating furnace section comprises two groups of second side heating mechanisms for heating the side parts of the strip steel, and the two groups of second side heating mechanisms are arranged on the transmission side and the operation side of the furnace body respectively.

As one embodiment, the tempering cooling section comprises a tempering cooling front section and a tempering cooling rear section, wherein the tempering cooling front section is provided with a circulating gas injection cooling mechanism, and the tempering cooling rear section is provided with an air injection cooling mechanism and/or a water spray cooling mechanism.

As one of the implementation modes, the product collecting unit comprises a strip steel coiling mechanism connected with the slitting shears, the strip steel coiling mechanism comprises a coiling machine, a steering pinch roll and a coil unloading vehicle, the steering pinch roll is connected with the coiling machine through a strip threading guide plate, and a bending machine is arranged on the feeding side of the steering pinch roll.

As one of the embodiments, at least one auxiliary press roller is arranged around the reel of the coiling machine, the axial direction of the auxiliary press roller is parallel to the axial direction of the reel, and the auxiliary press roller is provided with an auxiliary press roller driving unit so as to have a working position in rolling contact with the steel coil and a waiting position far away from the steel coil.

The invention also relates to a heat treatment method of the hot-rolled high-strength steel, which adopts the hot-rolled high-strength steel full-continuous heat treatment production system for production, wherein,

when the steel material is quenched, the steel material is rapidly heated to 750-1200 ℃ at the speed of 15-30 ℃/s, and the temperature is kept for 2-8 minutes, so as to obtain the austenitic structure of the steel material with the target form; cooling the quenched and heated steel material to a target quenching final cooling temperature by adopting a multi-stage quenching cooling mode so as to obtain a quenched martensitic structure in a target form;

Heating the steel material to 150-700 ℃ and preserving heat for 1-5 min when tempering the steel material; and cooling the steel material to room temperature by adopting a sectional cooling mode to obtain a stable tempered structure at room temperature.

The invention has at least the following beneficial effects: the production system provided by the invention can realize full-continuous heat treatment production of the hot-rolled high-strength steel, can obviously improve the heat treatment production efficiency of the hot-rolled high-strength steel, shortens the process flow, saves the investment and reduces the operation energy consumption.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the composition of a hot rolled high strength steel fully continuous heat treatment production system provided by the embodiment of the invention;

FIG. 2 is a schematic diagram of a strip steel quenching and tempering system according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a quenching apparatus according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating an operating state of a cooling mechanism according to an embodiment of the present invention;

FIG. 5 is a schematic view showing a state of a strip steel coiling system in an initial stage of coiling according to an embodiment of the present invention;

FIG. 6 is a schematic representation of the state of the strip coiling system at the end of coiling provided by the embodiment of the invention;

fig. 7 is a schematic structural view of a winding jaw according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely, and it is apparent that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

Referring to fig. 1, the embodiment of the invention provides a full-continuous heat treatment production system for hot rolled high-strength steel, which comprises an uncoiler 1, a welding machine 2, a quenching device, a tempering device, a slitting shear 7 and a product collecting unit which are sequentially connected in the running direction of the steel, wherein the quenching device comprises a quenching heating section 51 and a quenching cooling section 52 which are sequentially arranged in the running direction of the steel, and the tempering device comprises a tempering heating section 53 and a tempering cooling section 54 which are sequentially arranged in the running direction of the steel.

The production system can be suitable for heat treatment production of high-strength strip steel, the uncoiler 1 is used for uncoiling a steel coil, the uncoiler 1 is conventional equipment in the field, and specific structures are not repeated here. In order to satisfy the uncoiling of high-strength steel, the uncoiler 1 can comprise an anti-wrinkling roller for preventing strip steel from wrinkling and a pressing roller for preventing a steel coil from loosening; because the hot-rolled tape coiling head has poor plate type quality, a clamp type uncoiler is preferably adopted to improve the tape threading efficiency; further preferably, a double-channel uncoiling mode is adopted, so that the coil replacement downtime of the inlet section is reduced, and the production efficiency is improved.

The production system can be also suitable for heat treatment production of high-strength steel plates, so that the uncoiler 1 can be idle, and the steel plates can be conveyed to a downstream process through a conveying roller way; that is, the production system is preferably a production system capable of simultaneously satisfying heat treatment of a high-strength steel strip and a high-strength steel sheet.

Further preferably, the outlet side of the uncoiler 1 is provided with a clamping and straightening machine for clamping and conveying the strip head and primarily straightening the incoming steel coil, the straightening machine can adopt a double-roller system multi-roller system with separated transmission, and different roller systems are adopted for strip steel with different thicknesses, so that the straightening precision can be improved, the stress of a transmission roller is reduced, and the breakage of the roller is prevented. Optionally, the outlet side of the clamping and straightening machine is provided with a slitting shear 7 and a waste output device for cutting off the waste at the head of the steel coil. As can be easily seen, the above-mentioned sandwiching straightener, slitter-shears 7 are arranged between the uncoiler 1 and the welder 2.

The welding machine 2 is used for connecting the front and rear heads and the rear heads of steel materials, and ensures that the unit can realize full continuous production. Considering that the alloy content of the hot-rolled high-strength steel is high and the toughness is poor, the welding mode of the welding machine 2 is preferably laser arc composite welding, and the toughness of the welding line can be improved through reasonable selection of welding wire materials. Optionally, the welder 2 is provided with a crescent shear, a centering device, a trimming device and a punching device. Further preferably, an induction heating device is configured on the outlet side of the welding machine 2, and is used for performing on-line heat treatment on the welding seam, so that the internal stress of the welding seam is reduced, the tissue uniformity of a heat affected zone is improved, and the comprehensive mechanical property of the welding seam is improved.

Further preferably, as shown in fig. 1, a first loop 3 is arranged between the welding machine 2 and the quenching device, and the first loop 3 can store strip steel so as to ensure that the process section can continuously run at a constant speed, and the loop can be in the form of a multi-layer horizontal loop, a vertical loop or a pit loop.

Further preferably, as shown in fig. 1, a steel pretreatment unit 41 is arranged between the welding machine 2 and the quenching device, and the steel pretreatment unit 41 can adopt one or more of a shot blasting machine, a straightening machine and a brush roll. The pretreatment equipment is preferably arranged simultaneously, wherein the shot blasting machine sprays cast steel shots on the surface of the strip steel at a high speed to remove iron scales on the surface of the strip steel, so that the strip steel has good surface quality before entering a heating furnace; the brush roller is arranged at the outlet side of the shot blasting machine and is used for removing residual steel shots and oxide scale floating ash on the surface of the strip steel; the straightening machine is arranged at the outlet side of the brush roller and is used for straightening the strip steel, so that the strip steel is guaranteed to have a good plate shape before entering the quenching furnace, and the straightening mode of the straightening machine preferably adopts tension straightening or tension roller straightening in consideration of poor plasticity of hot-rolled high-strength steel, and the maximum surface elongation of the strip steel is reduced through the offset of a neutral layer, so that the surface of the strip steel is prevented from cracking in the straightening process. Further, tension roller sets are arranged at the inlet and outlet of the shot blasting machine and the inlet and outlet of the straightening machine, and are used for providing the tension required by strip steel in the shot blasting and straightening processes and isolating the tension.

In one embodiment, as shown in fig. 1, a temperature straightening device is arranged between the quenching device and the tempering device and is used for straightening quenched and cooled steel, and a temperature straightening mode is adopted, so that the deformation resistance of high-strength steel in the straightening process can be reduced, the straightening difficulty is reduced, and meanwhile, the temperature rise amplitude of a subsequent tempering heating section 53 can be reduced, and the energy consumption is reduced. Preferably, the straightening temperature of the temperature straightening device is controlled to be 100-300 ℃.

Further preferably, as shown in fig. 1, a steel post-processing unit 42 is arranged between the tempering device and the slitting shears 7, and the steel pre-processing unit 41 may be one or more of a shot blasting machine, a straightening machine and a brush roll. The pretreatment equipment is preferably arranged simultaneously, wherein the shot blasting machine sprays cast steel shots on the surface of the strip steel at a high speed to remove iron scales on the surface of the strip steel, so that the strip steel has good surface quality before entering a heating furnace; the brush roller is arranged at the outlet side of the shot blasting machine and is used for removing residual steel shots and oxide scale floating ash on the surface of the strip steel; the straightening machine is arranged at the outlet side of the brush roller and is used for straightening the strip steel, the shape and the surface quality of the strip steel are further improved, the straightening form of the straightening machine preferably adopts tension straightening or tension roller straightening in consideration of poor plasticity of hot-rolled high-strength steel, the maximum elongation of the surface of the strip steel is reduced through the offset of a neutral layer, and the surface of the strip steel is prevented from cracking in the straightening process. Further, tension roller sets are arranged at the inlet and outlet of the shot blasting machine and the inlet and outlet of the straightening machine, and are used for providing the tension required by strip steel in the shot blasting and straightening processes and isolating the tension.

Further preferably, as shown in fig. 1, a second loop 6 is arranged between the tempering device and the slitting shears 7, which second loop 6 can store strip steel to ensure a continuous constant speed operation of the process section, and the loop can be in the form of a multi-layer horizontal loop or a pit loop.

Further preferably, a fine straightening machine is arranged between the tempering device and the slitting shear 7 for final straightening of the finished steel product, ensuring the surface flatness of the strip steel to be less than 5I. The straightening form adopts one or more of withdrawal straightening, roller straightening or tension roller straightening. Optionally, a roller coater and a hot air dryer are arranged at the outlet of the fine straightening machine and are used for carrying out surface pretreatment on the strip steel and rapidly drying the strip steel, so that the strip steel is prevented from being rusted or other surface defects are prevented from being generated in the storage and transportation process.

The slitting shears 7 are used for cutting finished steel materials to a fixed length, and meet the requirements of users on steel materials with different lengths. The slitting shear 7 can adopt a flying shear or a shearing stopping mode, and the flying shear or the shearing stopping mode has the function of rapidly changing the shearing edge, or adopts a mode of 'one standby for one use', so that the downtime of an outlet section caused by changing the shearing edge can be effectively shortened.

Depending on the product form of the object, the product collection unit may be a coiler or a stacker 8, preferably a double channel is arranged on the outlet side of the slitter 7, wherein one channel is adapted to guide the strip product to the coiler and the other channel is adapted to transport the sheet to the stacker 8. If the finished product is delivered in a plate state, after the steel material is cut to length by the slitting shears 7, the qualified steel plate enters the stacker 8 for stacking, and the stacking plate is transported to a packaging unit by the conveying roller way for offline packaging; if the finished product is delivered in a coiled state, the finished product strip steel is subjected to surface treatment and then directly enters a coiling machine for coiling. When in coiled goods supply, the steel coil can be supplied after subsequent pickling, galvanization and finishing, which is beneficial to enriching the product types.

The production system provided by the embodiment can realize the full-continuous heat treatment production of the hot-rolled high-strength steel, can obviously improve the heat treatment production efficiency of the hot-rolled high-strength steel, shortens the process flow, saves the investment and reduces the operation energy consumption.

Example two

The embodiment provides a strip steel quenching and tempering system which can be used in the hot-rolled high-strength steel full-continuous heat treatment production system provided in the first embodiment.

As shown in fig. 2, the strip steel quenching and tempering system comprises a strip steel quenching device and a strip steel tempering device, wherein the strip steel quenching device comprises a quenching heating section 51 and a quenching cooling section 52 which are sequentially arranged along the strip steel running direction, and the quenching heating section 51 comprises a first longitudinal magnetic induction heating furnace section 512, a transverse magnetic induction heating furnace section 513 and a first soaking furnace section 515 which are sequentially arranged along the strip steel running direction; the strip steel tempering device comprises a tempering heating section 53 and a tempering cooling section 54 which are sequentially arranged along the strip steel running direction, wherein the tempering heating section 53 comprises a second longitudinal magnetic induction heating furnace section 532 and a second soaking furnace section 534 which are sequentially arranged along the strip steel running direction.

In the case of the arrangement of the temperature correction device 55 between the quenching device and the tempering device, the temperature correction device 55 is correspondingly arranged between the quenching cooling section 52 and the tempering heating section 53.

The first longitudinal magnetic induction heating furnace section 512 may be a conventional longitudinal magnetic induction heating device in the art, the transverse magnetic induction heating furnace section 513 may be a conventional transverse magnetic induction heating device in the art, for example, a "transverse magnetic line induction heating device with variable magnetic path width" disclosed in CN01117018.2, for example, a "broad area induction heating device for uniformly heating strip steel" disclosed in CN201410011044.4, and the specific structure is not described here. In this embodiment, in the first longitudinal magnetic induction heating furnace section 512, the power supply system adopts a 10khz power frequency IGBT power supply technology, the inductor adopts a single turn whole plate induction coil technology, and specifically, the cavity sealing is realized through a muffle furnace structure in the inductor coil, and the cavity sealing device adopts a double-layer sealing sleeve structure technology; in the transverse magnetic induction heating furnace section 513, a power supply system adopts a 1khz power frequency IGBT power supply technology, an inductor adopts a multi-turn induction coil technology, and particularly, cavity sealing is realized through a muffle furnace structure in the inductor coil, and a cavity sealing device adopts a double-layer sealing sleeve structure technology. Preferably, in the first longitudinal magnetic induction heating furnace section 512, the strip steel is rapidly heated to about 700 ℃ from normal temperature, so that high comprehensive heat efficiency is ensured while rapid heating is realized; in the transverse magnetic induction heating furnace section 513, the strip steel is heated from 700 ℃ to a target quenching temperature (e.g. about 950 ℃), so that rapid and efficient heating after the Curie temperature point is realized.

The strip steel subjected to quenching and heating can be heated and subjected to uniform temperature through the first soaking furnace section 515, austenitizing and heat preservation of the strip steel are realized, the performance of the strip steel is effectively improved, and the uniformity of the performance of the strip steel is promoted; preferably, an electric radiant heating pipe is configured in the first soaking furnace section 515, and a good soaking and heat preserving effect can be achieved by adopting an electric radiant heating technology; the electromagnetic induction heating technology and the electric radiant tube heating technology are adopted to realize rapid quenching heating and heat preservation soaking, so that the length of a quenching heating furnace section can be greatly reduced, the length of the furnace section is saved by more than 1/2, and intensive short-flow production is realized. Further preferably, a circulating fan for enhancing the turbulence of the furnace gas is further arranged in the first soaking furnace section 515, so that the temperature uniformity in the furnace section can be improved, and the operation energy consumption can be reduced.

Likewise, the second longitudinal magnetic induction heating furnace 532 may be a conventional longitudinal magnetic induction heating apparatus in the art, and the specific structure thereof will not be described herein. In this embodiment, in the second longitudinal magnetic induction heating furnace section 532, the power supply system adopts a 10khz power frequency IGBT power supply technology, the inductor adopts a single turn whole plate induction coil technology, and specifically, the cavity is sealed by a muffle furnace structure in the inductor coil, and the cavity sealing device adopts a double-layer sealing sleeve structure technology. Wherein, the second longitudinal magnetic induction heating furnace section 532 can realize rapid tempering heating before 700 ℃ of the strip steel, and particularly can realize low-temperature tempering (150-250 ℃), medium-temperature tempering (350-500 ℃) and high-temperature tempering (650-700 ℃) according to tempering process requirements.

The second soaking furnace section 534 can heat and uniformize the temperature of the tempered and tempered strip steel, and the uniformity of the tissue and carbide precipitation in the width direction of the strip steel is improved, so that the performance uniformity of strip steel products is improved. Preferably, an electric radiant heating pipe is disposed in the second soaking furnace section 534, and a better soaking and heat preserving effect can be achieved by adopting an electric radiant heating technology; the electromagnetic induction heating technology and the electric radiant tube heating technology are adopted to realize rapid tempering heating and heat preservation soaking, so that the length of a tempering heating furnace section can be greatly reduced, the length of the furnace section is saved by more than 1/2, and intensive short-flow production is realized. Further preferably, a circulating fan for enhancing the turbulence of the furnace gas is further provided in the second soaking furnace section 534, so that the temperature uniformity in the furnace section can be improved, and the operation energy consumption can be reduced.

Further optimizing the above-mentioned belted steel guenching unit, the quenching heating section 51 further includes a first side heating furnace section 514, the first side heating furnace section 514 is disposed between the transverse magnetic induction heating furnace section 513 and the first soaking furnace section 515, the first side heating furnace section 514 includes two sets of first side heating mechanisms for heating the belted steel side, and the two sets of first side heating mechanisms are disposed on the driving side and the operating side of the furnace body. By arranging the first edge heating furnace section 514 after the first longitudinal magnetic induction heating furnace section 512 and the transverse magnetic induction heating furnace section 513, the temperature difference region at the edge of the strip steel generated by combined heating of longitudinal magnetic induction heating and transverse magnetic induction heating can be supplemented, so that the condition of non-uniformity of the temperature in the width direction of the strip steel is reduced or avoided, the quenching quality of the strip steel is remarkably improved, the uniformity of tissue and carbide precipitation in the width direction of the strip steel is improved, and the uniformity of the performance in the width direction of the product is ensured.

The first side heating means preferably also adopts a magnetic induction heating technique, and specifically, the first side heating means includes a first side magnetic induction heater disposed on a side corresponding to the furnace body and a first magnetic shielding structure for limiting a magnetic field of the first side magnetic induction heater to a side corresponding to the strip steel. A part of the magnetic field is selectively shielded by the first magnetic shielding structure, and the magnetic field of the allowed part extends along a set direction, so that the magnetic field can act on the to-be-heated edge area of the strip steel, and the direction of the magnetic field accords with a preset direction, for example, the heating is performed along the width direction or the length direction of the strip steel. The magnetic field regulation capability of the first side magnetic induction heater is matched with the selective shielding effect of the first magnetic shielding structure, so that good magnetic field regulation capability can be obtained, and the magnetic induction heating effect in a specified direction and at a specified intensity can be realized. The first magnetic shielding structure may, for example, use a magnetic shielding case and provide a magnetic field channel on the magnetic shielding case, and in another embodiment, the first magnetic shielding structure includes a first shielding copper plate disposed on a corresponding side of the furnace body, where a plate surface of the first shielding copper plate is parallel to a running direction of the strip steel, and obviously, an arrangement position of the first shielding copper plate is satisfied to enable a magnetic field of the first side magnetic induction heater to act on an edge area to be heated of the strip steel. In a preferred scheme, the width of the magnetic field restrained by the first magnetic shielding structure is 45-60 mm, preferably about 50mm, namely, one side boundary of the magnetic field restraining structure for supplementing heat to the edge of the strip steel is the edge of the strip steel, and the other side boundary of the magnetic field restraining structure is 45-60 mm away from the edge of the strip steel, so that the temperature difference area of the edge of the strip steel can be well covered. In an alternative solution, the first side electromagnetic induction heater may be driven by a travelling trolley to approach or depart from the strip steel running channel, so as to switch between a working state and a standby state of the first side electromagnetic induction heater, and adjust a target magnetic field action position of the first side electromagnetic induction heater according to a specific working condition, where: if the first magnetic shielding structure is a static shielding structure, the first side electromagnetic induction heater can be driven to move to heat different side width ranges of the strip steel or adapt to strip steel heating operations with different width specifications; if the first magnetic shielding structure is a dynamic shielding structure, the width and/or the direction of the magnetic field can be regulated, and the magnetic field heating area can be controlled more accurately by combining the movement of the first side electromagnetic induction heater, so that the heating uniformity effect of the side part of the strip steel can be improved.

As shown in fig. 2, an inlet sealing chamber 511 is provided at the inlet side of the furnace body of the above-mentioned strip steel quenching device, and an outlet sealing chamber 516 is provided at the outlet side of the furnace body, so as to ensure the stability of the temperature field in the furnace.

Further optimizing the above strip tempering device, the tempering heating section 53 further includes a second side heating furnace section 533, the second side heating furnace section 533 is disposed between the second longitudinal magnetic induction heating furnace section 532 and the second soaking furnace section 534, the second side heating furnace section 533 includes two sets of second side heating mechanisms for heating the side portion of the strip, and the two sets of second side heating mechanisms are disposed on the driving side and the operating side of the furnace body. By arranging the second side heating furnace section 533 after the second longitudinal magnetic induction heating furnace section 532, the temperature difference region at the side of the strip steel generated by longitudinal magnetic induction heating can be supplemented, so that the condition of non-uniformity of the temperature in the width direction of the strip steel is reduced or avoided, the tempering quality of the strip steel is remarkably improved, the uniformity of the structure and carbide precipitation in the width direction of the hot-rolled or cold-rolled strip steel is improved, and the uniformity of the performance in the width direction of the product is ensured. Similarly, the second side heating mechanism comprises a second side magnetic induction heater arranged on the corresponding side of the furnace body and a second magnetic shielding structure for limiting the magnetic field of the second side magnetic induction heater to the corresponding side of the strip steel. Selectively shielding a part of the magnetic field by the second magnetic shielding structure, allowing the part of the magnetic field to extend along a set direction so that the magnetic field can act on the to-be-heated edge region of the strip steel, wherein the direction of the magnetic field accords with a preset direction, for example, the strip steel is heated along the width direction or the length direction; the magnetic field regulation capability of the second side magnetic induction heater is matched with the selective shielding effect of the second magnetic shielding structure, so that good magnetic field regulation capability can be obtained, and the magnetic induction heating effect in a specified direction and at a specified intensity can be realized. The second magnetic shielding structure may, for example, use a magnetic shielding case and provide a magnetic field channel on the magnetic shielding case, and in another embodiment, the second magnetic shielding structure includes a second shielding copper plate disposed on a corresponding side of the furnace body, where a plate surface of the second shielding copper plate is parallel to a running direction of the strip steel, and obviously, an arrangement position of the second shielding copper plate is satisfied to enable a magnetic field of the second side magnetic induction heater to act on an edge area to be heated of the strip steel. In the preferred scheme, the width of the magnetic field restrained by the second magnetic shielding structure is 45-60 mm, preferably about 50mm, namely one side boundary for supplementing heat to the edge of the strip steel is the edge of the strip steel, and the other side boundary is 45-60 mm away from the edge of the strip steel, so that the temperature difference area of the edge of the strip steel can be well covered. Likewise, the second side electromagnetic induction heater is preferably driven by a travelling trolley to move closer to or farther from the strip running channel.

Further optimizing the strip tempering device, the cooling mechanism configured by the tempering cooling section 54 comprises a circulating gas injection cooling mechanism 541, namely, the heated gas after the strip is cooled in the device is pumped out by a circulating fan, is cooled by a heat exchanger and then becomes cold gas, and the cold gas is injected to the upper surface and the lower surface of the strip by the circulating fan at a certain pressure, so that the degree of the increase of the oxidation layer of the strip can be obviously reduced. The temperature of the strip steel can be rapidly cooled to-500 ℃ by the circulating gas blowing cooling mechanism 541. Preferably, the circulating gas injection cooling mechanism 541 is disposed in the furnace body of the tempering heating section 53 and at the tail of the furnace body; based on the structure, on one hand, the newly added oxide layer of the strip steel can be further reduced, and on the other hand, the compactness of the strip steel tempering device can be further improved. Similarly, as shown in fig. 2, an inlet sealing chamber 531 is provided on the inlet side of the furnace body of the strip tempering device, and outlet sealing chambers 535 are provided on the outlet side of the furnace body, so as to ensure the stability of the temperature field in the furnace; and the circulating gas injection cooling section is sealed through the outlet sealing chamber 535 of the furnace body, so that the number of sealing devices can be reduced, and the equipment cost can be reduced. Further preferably, as shown in fig. 2, the cooling mechanism of the tempering cooling section 54 further includes an off-furnace cooling mechanism 542, and the off-furnace cooling mechanism 542 employs an air-blown cooling mechanism and/or a water-sprayed cooling mechanism to cool the strip steel from around 500 ℃ to normal temperature.

In the above-mentioned steel strip quenching device, the following cooling scheme is preferably adopted:

as shown in fig. 3, a quenching cooling device is provided, which comprises a plurality of cooling boxes 521 sequentially arranged along the running direction of strip steel, an intermediate tension roller 523 is arranged between two adjacent cooling boxes 521, a wringing roller 524 is arranged at the outlet side of a tail end cooling box 521, a quenching cooling mechanism 522 is arranged in the cooling boxes 521, and the cooling mechanism comprises an aerosol cooling mechanism and/or a water spray cooling mechanism. Among them, an inlet pinch roller 525 for pinching the strip steel for stable cooling is preferably arranged on the inlet side of the head-end cooling box 521; it is understood that a roller conveyor is arranged in each cooling box 521 for supporting the strip.

The tension control on the strip steel operation can be realized through the intermediate tension roller 523, the rigidity of the strip steel is improved, the strip steel shape is well controlled, and the large shape change caused by quenching cooling is avoided, so that the strip steel quality and the product performance are improved. The intermediate tension rollers 523 are preferably provided with at least two groups to realize tension sectional control, so that the tension control can be correspondingly performed according to the quenching and cooling process of the strip steel, the strip steel shape control is better, and the strip steel shape defect caused by internal stress in the cooling process is prevented; the above-mentioned cooling boxes 521 are preferably not less than three. Further, the intermediate tension roller 523 is driven by a variable frequency motor; in an alternative, the intermediate tension roller 523 includes an upper movable roller and a lower fixed roller, and the upper movable roller is driven to be lifted by a driving device such as a hydraulic cylinder, so that the gap between the intermediate tension roller 523 can be adjusted as needed.

The wringing roller 524 can partially remove the residual cooling water on the surface of the strip steel, and the wringing roller 524 is conventional equipment in the metallurgical field, and the specific structure is not described herein. Further, as shown in fig. 3, a drying unit 526 is disposed at the outlet side of the wringing roller 524, so as to further remove residual water stains on the surface of the strip steel and ensure the surface quality of the strip steel; the drying unit 526 may be dried by hot air, for example, and includes a drying box and a hot air supply pipe provided on the drying box.

It will be appreciated that the above-described aerosol-cooling mechanism comprises an aerosol-cooling nozzle which may be a conventional two-fluid nozzle, the cooling water forming atomized water under the action of the high pressure gas; the water spray cooling mechanism comprises a water spray nozzle, and the cooling water can form atomized water under the mechanical action. The atomized cooling medium is used for cooling the strip steel, so that the cooling effect on the strip steel is good, quenching cooling parameters such as quenching cooling rate, strip steel final cooling temperature and the like are easy to control, good strip steel quality and strip shape are obtained, and the requirements of continuous quenching or isothermal quenching of the strip steel, especially the production of thin strip steel, can be well met. Wherein, the control of the cooling area speed and the final cooling temperature of the strip steel can be controlled by precisely controlling the cooling water quantity, the cooling time and the like.

In this embodiment, an aerosol cooling mechanism is preferably used, and the atomization effect of the cooling water is good. As shown in fig. 3, a mist discharge pipe 527 is arranged on the cooling box 521, and the gas medium in the cooling box 521 is pumped out by the action of an induced draft fan; a gas-water separation device may be provided at the mist discharge port of the cooling tank 521.

Continuing the quenching cooling device, the quenching cooling mechanism 522 comprises an upper cooling unit arranged above the strip steel running channel and a lower cooling unit arranged below the strip steel running channel, wherein the upper cooling unit and the lower cooling unit comprise a plurality of cooling nozzles 5221 which are arranged at intervals along the width direction of the strip steel running channel, and the cooling nozzles 5221 adopt aerosol cooling nozzles or water mist nozzles. The upper cooling unit is used for cooling the upper surface of the strip steel, the lower cooling unit is used for cooling the lower surface of the strip steel, the upper cooling unit and the lower cooling unit are matched to obtain the required cooling rate and the final cooling temperature of the strip steel, and the cooling uniformity of the strip steel can be improved.

In a further preferred scheme, each group of cooling units comprises a middle nozzle for cooling the middle part of the strip steel and side nozzles for cooling the sides of the strip steel, each middle nozzle of each group of cooling units is arranged on a first medium supply pipe, each side nozzle of each group of cooling units is arranged on a second medium supply pipe, namely, the cooling of the middle part of the strip steel and the cooling of the sides of the strip steel are mutually independent, different cooling rates can be adopted in different areas of the strip steel in a targeted manner, the cooling uniformity in the width direction of the strip steel is ensured, and therefore, a good strip steel shape is obtained, and meanwhile, the consumption of cooling medium can be saved.

Further preferably, as shown in fig. 4, in the upper cooling unit, a first water baffle 5222 is disposed below at least part of the cooling nozzles 5221, at least part of the plate body of the first water baffle 5222 overlaps with the spraying area of the corresponding cooling nozzle 5221, or at least part of the plate body of the first water baffle 5222 extends onto the spraying path of the corresponding cooling nozzle 5221, on one hand, the spraying range of the cooling nozzle 5221 can be adjusted by the first water baffle 5222, so that the cooling effect of the upper cooling unit can be adjusted according to different strip steel conditions, and on the other hand, the cooling width of the upper cooling unit can be adjusted to adapt to the quenching cooling requirements of strip steel with different widths. It will be appreciated that the first deflector 5222 described above is provided for side nozzles, particularly the outermost side nozzles. It may be further designed that at least part of the first water baffle 5222 and the spray area corresponding to the cooling nozzle 5221 are adjustable in overlapping area, and the cooling effect and/or the cooling width adjusting effect of the upper cooling unit are better; in one embodiment, the first water baffle 5222 is configured with a lifting driving unit, for example, a linear driving device such as an air cylinder drives the first water baffle 5222 to lift, so as to adjust the shielding area of the first water baffle 5222 to the cooling nozzle 5221, however, a manner of horizontally driving the first water baffle 5222 is also possible, which will not be described in detail herein.

Further preferably, as shown in fig. 4, the first water baffle 5222 is a trough plate with two wide sides and a low middle, so that the cooling water blocked by the first water baffle 5222 can be prevented from dripping onto the surface of the strip again, and the blocked cooling water can be drained and recovered by the first water baffle 5222.

Likewise, the above water blocking structure may be used in the lower cooling unit to adjust the cooling effect and/or cooling width of the lower cooling unit, that is, a second water blocking plate 5223 is disposed above at least part of the cooling nozzles 5221, and at least part of the plate body of the second water blocking plate 5223 overlaps with the spraying area of the corresponding cooling nozzle 5221. The second water baffle 5223 can be fixedly installed or movably installed.

Example III

The embodiment of the present invention provides a strip coiling mechanism 9 which can be used in the above-described embodiment one as a collection scheme of the product collection unit therein.

As shown in fig. 5 and 6, the strip coiling mechanism 9 comprises a coiling machine, a steering pinch roll 92 and a coil unloader 96, wherein the steering pinch roll 92 is connected with the coiling machine through a strip threading guide plate, and a bending machine 93 is arranged on the feeding side of the steering pinch roll 92.

The coiler, the steering pinch roller 92, and the unwind stand 96 are all conventional in the art, and the specific construction thereof will not be described here.

The existing equipment capable of bending strip steel is suitable for the embodiment. In a preferred solution, as shown in fig. 5 and 6, the bending machine 93 includes a casing and a plurality of bending rollers disposed in the casing, wherein a part of the bending rollers are disposed above the strip steel running channel, the rest of the bending rollers are disposed below the strip steel running channel, and each bending roller is disposed in a staggered manner along the strip steel running direction and is respectively connected with a lifting driving mechanism. The bending operation and the bending degree control of the strip steel can be realized by controlling the height position of each bending roller; in particular, the purpose of straightening the strip steel can be achieved by controlling the height position of each bending roller to control the bending amount of the strip steel at the corresponding position. In the embodiment, a 4-roller bending machine 93 is adopted, and two bending rollers are respectively arranged above and below the strip steel running channel.

Further, as shown in fig. 5 and 6, at least one auxiliary pressing roller 95 is disposed around the drum 91 of the coiler, the axial direction of the auxiliary pressing roller 95 is parallel to the axial direction of the drum 91, and the auxiliary pressing roller 95 is provided with an auxiliary pressing roller 95 driving unit so as to have an operating position in rolling contact with the coil 97 and a standby position away from the coil 97. The driving unit of the auxiliary pressing roller 95 is preferably driven by a hydraulic cylinder, and may adopt a mode of driving the auxiliary pressing roller 95 to swing to switch between a working position and a standby position, or a mode of driving the auxiliary pressing roller 95 to perform linear motion to switch between the working position and the standby position; in the embodiment, the latter mode is adopted, namely the auxiliary pressing roller 95 moves linearly between the working position and the standby position, so that the pressing effect on the strip steel is better; further, the auxiliary pressing roller 95 makes a linear motion along the radial direction of the winding drum 91, that is, the extension line of the motion path of the auxiliary pressing roller 95 passes through the axis of the winding drum 91, and along with the change of the diameter of the steel coil 97, the pressing position of the auxiliary pressing roller 95 can be ensured to be unchanged, so that accurate control is facilitated.

In a preferred embodiment, as shown in fig. 5 and 6, the auxiliary pressing rollers 95 are plural and are sequentially arranged in the circumferential direction of the drum 91, and it is apparent that the auxiliary winding effect can be further improved by using the plural auxiliary pressing rollers 95 so that the strip steel is more adhered to the drum 91. In one embodiment, as shown in fig. 5 and 6, the working position of each auxiliary pressing roller 95 is distributed between 6 o ' clock and 12 o ' clock of the steel coil 97, and since the coil unloading vehicle 96 is generally arranged below the 6 o ' clock position of the steel coil 97, the auxiliary pressing rollers 95 need to avoid the position or one of the auxiliary pressing rollers 95 is arranged on the coil unloading vehicle 96; the above solution is particularly suitable for reeling up. Of course, for the down-winding scheme, the arrangement position of each auxiliary pressing roller 95 may be designed accordingly, for example, the working positions of each auxiliary pressing roller 95 are distributed between 9 o 'clock and 3 o' clock of the steel coil 97, etc.

Alternatively, the working position of one of the auxiliary rolls 95 is located near the initial position of the jaw of the reel 91, for example, for the case of a reeling-up solution and the working positions of the auxiliary rolls 95 are distributed between the 6 o ' clock and 12 o ' clock positions of the coil 97, it is possible to design the working position of one of the auxiliary rolls 95 to be located at the 12 o ' clock position of the coil 97. The strip steel can be attached to the winding drum 91/the steel coil 97 during winding, and the problem that the strip steel bulges near the jaw during winding of steel types such as high-strength steel can be avoided.

In particular, the coil stripper 96 is provided with a carrier roller suitable for rolling contact with the steel coil 97, and when the carrier roller contacts with the steel coil 97 and each auxiliary pressing roller 95 is in a working position, the carrier roller and each auxiliary pressing roller 95 are combined to form a coil assisting roller set; at the end of winding, auxiliary pressing rollers 95 and carrier rollers on the coil unloading vehicle 96 can be combined to form a coil assisting roller set to assist in completing the winding of the belt tail, thereby having the function of a coil assisting device.

The strip winding mechanism 9 is connected, and the threading guide plate is used for guiding the strip to the winding machine at the initial winding stage and the final winding stage. In one embodiment, as shown in fig. 5 and 6, the threading guide plate includes an upper guide plate 941 and a lower guide plate 942 separately arranged at the upper and lower sides of the strip steel design steel line, and the upper guide plate 941 and the lower guide plate 942 are respectively connected with a guide plate driving unit; the steel wire is designed, namely, the steel wire between the steering pinch roll 92 and the winding drum 91 during normal winding, namely, a steel wire running channel is expected to be formed between the steering pinch roll 92 and the winding drum 91; the guide plate driving unit may adopt conventional driving devices such as hydraulic cylinders, and a specific guide plate driving manner is a conventional technology in the art, and will not be described herein. Through the cooperation of the upper guide plate 941 and the lower guide plate 942, the upper surface and the lower surface of the strip steel can be limited respectively, a guide crack can be formed between the upper surface and the lower surface, the strip steel can be guided to a coiling machine more accurately, and particularly, the problem of difficult coiling caused by the problem of high-strength steel plate shape can be solved to a certain extent. Further preferably, as shown in fig. 5 and 6, a guiding press roller (not shown) is disposed at the end of the upper guide plate 941, so that the strip steel can be applied to the lower guide plate 942 as closely as possible, which is convenient for coiling the strip steel, especially for guiding the high-strength strip steel smoothly and accurately to the jaw of the reel 91 in the initial stage of coiling. Optionally, the upper guide plate 941 and the lower guide plate 942 are telescopic guide plates, so that after the upper guide plate 941 and the lower guide plate 942 clamp the strip steel, the upper guide plate 941 and the lower guide plate 942 can move forward synchronously with the strip steel through the extending operation of the upper guide plate 941 and the lower guide plate, and the clamping and guiding effects on the strip steel are ensured.

According to the strip steel coiling mechanism 9 provided by the embodiment of the invention, through the arrangement of the bending machine 93, (1) the strip steel can be straightened in the initial coiling stage, the strip steel warping or the damage of the strip steel penetrating guide plate caused by the lower head is avoided, and the strip steel, particularly high-strength steel, can smoothly and accurately enter the jaw of the winding drum 91; (2) At the end of coiling, the sheared strip tail is free and has no tension, and the strip steel is bent by a bending machine 93 to generate plastic deformation to generate energy consumption, so that the post-tension can be provided for coiling; meanwhile, the strip steel is subjected to plastic deformation through the bending machine 93, the strip steel from the bending machine 93 has a spring compound curvature variable diameter slightly larger than the radius of the current coiled steel coil 97, and thus the resilience force of the outer-ring strip steel can be reduced to a great extent after the strip steel coil 97 is taken, and the subsequent operations such as bundling the strip steel coil 97 are facilitated. By providing the auxiliary press roller 95, the strip steel can be attached to the reel 91/coil 97 during coiling, the coiling effect of the strip steel is improved, and the problem that the strip steel bulges near the jaw during coiling of high-strength steel and other steel types can be avoided.

In a preferred embodiment, as shown in fig. 7, the jaw of the reel 91 includes a sector plate 911, a groove is formed on the sector plate 911, a fixed jaw plate 912 is disposed at a wall of one side of the groove, a movable jaw plate 913 and a jaw driving unit 914 for driving the movable jaw plate 913 to approach or separate from the fixed jaw plate 912 are disposed in the groove, an outlet guide plate 915 is disposed at a wall of the other side of the groove, a steel surface of the fixed jaw plate 912 is disposed obliquely, and an outer end of the steel surface of the fixed jaw plate 912 is located at a side of an inner end of the steel surface of the fixed jaw plate 912, which is adjacent to the outlet guide plate 915, and an outer surface of the outlet guide plate 915 is an arc-shaped guide surface and a space enclosed by the steel surface of the fixed jaw plate 912 is gradually widened from inside to outside.

Preferably, the jaw driving unit 914 is a hydraulic cylinder, and a hydraulic jaw is used to improve a larger clamping force, so that, on one hand, an initial coiling tension of the strip steel, especially high-strength steel, can be met, and on the other hand, the depth of the strip head entering the jaw can be reduced, thereby reducing the rebound force of the strip steel, especially high-strength steel, and avoiding the condition that the strip head of the inner coil protrudes. Alternatively, as shown in fig. 7, the jaw driving unit 914 is fixedly installed at the bottom of the groove.

In one embodiment, the steel surface of the movable jaw plate 913 has a plurality of saw teeth formed thereon, and it is further preferable that the steel surface of the movable jaw plate 913 is designed as a saw tooth surface; the friction force between the saw tooth pliers steel surface and the strip steel can be increased, and the pliers effect on the strip steel is improved.

Optionally, the steel surface of the fixed jaw plate 912 is smooth, and the tape head is easier to be pulled out of the jaws during the coil stripping process. The saw-tooth pliers steel surface of the movable jaw plate 913 is matched, so that the coil stripping operation of the coiling machine is convenient while the reliable clamping of the strip steel is ensured.

As can be appreciated, after the strip head is clamped by the fixed jaw plate 912 and the movable jaw plate 913, the strip exits the jaws via the exit guide plate 915 and is wound on the reel 91; the outer surface of the exit guide 915 is adapted to contact the supporting strip; the steel clamp of the fixed jaw plate 912 is inclined towards the other side wall of the groove, the space formed by surrounding the groove bottom is a triangle space gradually expanding from inside to outside, and the outlet guide plate 915 gradually bulges towards the groove opening side from the groove bottom, so that the strip steel is conveniently and smoothly attached to the outlet guide plate 915. Based on the structure, through the design of the outlet guide plate 915, the strip steel is enabled to have no larger bending, turning and the like as much as possible when being discharged from the jaw, so that the plastic deformation of the strip steel is reduced when being discharged from the jaw, the situation that the strip steel is broken due to the occurrence of cracks on the surface of the strip steel is prevented, meanwhile, the resilience force of the strip steel is reduced, and the difficulty of discharging the strip steel from the jaw is reduced.

Further preferably, the arcuate guide surface comprises a first arcuate segment and a second arcuate segment of differing curvature, the second arcuate segment having the same curvature as the outer surface of the adjacent sector plate 911 and being smoothly joined, the first arcuate segment being joined to the other end of the second arcuate segment (i.e., the end adjacent to the fixed jaw plate 912); with this structure, the strip exiting the jaws can be smoothly attached to the sector plate 911/the reel 91.

To facilitate the placement of the jaw drive unit 914 and the exit guide plate 915, the exit guide plate 915 may be slotted to accommodate the jaw drive unit 914 described above; or two groups of jaw driving units 914 are arranged, and the two groups of jaw driving units 914 are respectively arranged at two ends of the outlet guide plate 915; and other arrangements, not described in detail herein.

Example IV

The embodiment of the invention provides a heat treatment method for hot-rolled high-strength steel, which adopts the full-continuous heat treatment production system for hot-rolled high-strength steel provided by the first embodiment to carry out production, wherein,

(1) When the steel material is quenched, the steel material is rapidly heated to 750-1200 ℃ at a speed of 15-30 ℃/s, and is kept for 2-8 minutes, so as to obtain an austenite structure of the steel material in a target form, preferably a uniform and fine austenite structure; particularly, by adopting the magnetic induction quenching heating mode in the second embodiment, the austenite transformation incubation period can be shortened and the austenite nucleation rate can be improved based on the rapid heating technology, so that a uniform and fine austenite structure can be obtained, and a structure foundation is provided for the good mechanical property of the final product.

(2) And cooling the quenched and heated steel material to a target quenching final cooling temperature by adopting a multi-stage quenching cooling mode to obtain a quenched martensitic structure in a target form, preferably a uniform and fine quenched martensitic structure. The adoption of a multi-stage quenching cooling mode can greatly reduce the internal stress generated in the quenching cooling process of the steel strip or the steel plate on the premise of ensuring the hardenability, and avoid serious plate type defects; for example, the quenching cooling method in the second embodiment is adopted.

(3) Heating the steel material to 150-700 ℃ and preserving heat for 1-5 min when tempering the steel material; so as to eliminate the internal stress of the steel material, ensure corresponding tissue transformation, improve the plastic toughness of the high-strength steel and obtain reasonable matching of strength, plasticity and toughness. For example, the magnetic induction tempering heating method in the second embodiment is adopted.

(4) And during tempering and cooling, cooling the steel material to room temperature in a sectional cooling mode to obtain a stable tempered structure at room temperature. Particularly, by adopting the tempering cooling scheme in the second embodiment, the cooling at the high temperature section of more than 250-350 ℃ adopts a protective gas circulation injection cooling technology, the strip steel is rapidly cooled at 30-50 ℃/s, the occurrence of tempering brittleness is avoided, and meanwhile, the oxidation of the strip steel is prevented; the low temperature Duan Lengque below 250-350 ℃ cools the strip steel to room temperature by air/water cooling, reduces tempering internal stress and obtains stable tempering state structure.

In addition, based on the strip coiling mechanism 9 provided in the third embodiment, the method for coiling the high-strength strip steel includes:

a. as shown in fig. 5, in the initial stage of coiling, the bending machine 93 is used for straightening the strip steel, so that the strip steel is prevented from warping or damaging a strip penetrating guide plate, and the strip steel, particularly high-strength steel, can smoothly and accurately enter the jaw of the winding drum 91; the specific straightening operation is described in the first embodiment, and will not be described here.

The strip is guided to the reel 91 by the steering pinch rollers 92 and the threading guides, which are conventional in the art and will not be described in detail here;

the jaw of the winding drum 91 clamps the strip steel, the winding drum 91 expands the diameter to establish initial tension, and when the jaw sequentially passes through the working positions of the auxiliary pressing rollers 95, the auxiliary pressing rollers 95 correspondingly press the strip steel on the winding drum 91, so that the coiler can ensure the strip steel coiling effect without the need of a full tension state. After a plurality of circles of strip steel are coiled in this way (3-5 circles are preferable), the coiling machine establishes full tension operation;

b. as shown in fig. 6, at the end of coiling, the strip is bent by the bending machine 93; the sheared strip tail is free and tension-free, and the strip steel is bent by the bending machine 93 to generate plastic deformation to generate energy consumption, so that the post-tension can be provided for coiling; meanwhile, the strip steel is subjected to plastic deformation through the bending machine 93, the strip steel from the bending machine 93 has a spring-back curvature variable diameter slightly larger than the radius of the current coiled steel coil 97, so that the resilience force of the outer-ring strip steel can be reduced to a great extent after the strip steel is coiled, and the subsequent operations such as bundling the steel coil 97 are facilitated.

Specifically, when the unreeling signal is received, the threading guide plate is in place (for the above-described structure including the upper guide plate 941 and the lower guide plate 942, only the lower guide plate 942 can be lifted), the pinch roller is pressed down, and the strip is bent by the bending machine 93; and after the slitting operation of the slitting shears is finished, the coiling machine continues coiling to finish coiling the belt tail. Preferably, the auxiliary pressing rollers 95 and the carrier rollers on the coil unloader 96 form a coil assisting roller set to assist in completing the coiling of the strip tail, namely, the auxiliary pressing rollers 95 are pressed against the steel coil 97, the coil unloader 96 is lifted to contact the carrier rollers with the steel coil 97, and the coil assisting device formed by the auxiliary pressing rollers 95 and the carrier rollers can effectively prevent the strip tail from rebounding under a tension-free state.

It will be appreciated that during normal winding, each auxiliary roller 95 is in standby position, the threading guide is also in idle position, the pinch rollers are open, and the bending machine 93 is open. When the coil stripping operation is completed, the coil stripping vehicle 96 contacts the strip steel, the jaw is opened, the diameter of the winding drum 91 is reduced by 20%, the winding drum is rotated forward by 45 degrees, the strip head is taken out of the jaw, the diameter is reduced to the minimum coil diameter after the diameter is expanded again, and then the coil is stripped.

In the hot-rolled high-strength steel heat treatment method, the finished steel material can be ensured to have good surface quality and shape through various strip steel surface protection measures and shape improvement measures which are configured in a whole system; meanwhile, the good surface quality and the shape of the strip steel ensure that the strip steel has good temperature uniformity in the heating and cooling processes, thereby ensuring that the product has good uniformity of tissue and mechanical properties.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. A full continuous heat treatment production system for hot-rolled high-strength steel is characterized in that: the device comprises an uncoiler, a welding machine, a quenching device, a tempering device, a slitting shear and a product collecting unit which are sequentially connected and arranged along the running direction of the steel, wherein the quenching device comprises a quenching heating section and a quenching cooling section which are sequentially arranged along the running direction of the steel, and the tempering device comprises a tempering heating section and a tempering cooling section which are sequentially arranged along the running direction of the steel;

the quenching heating section comprises a first longitudinal magnetic induction heating furnace section, a transverse magnetic induction heating furnace section and a first soaking furnace section which are sequentially arranged along the running direction of the steel material;

the quenching heating section further comprises a first side heating furnace section, the first side heating furnace section is arranged between the transverse magnetic induction heating furnace section and the first soaking furnace section, the first side heating furnace section comprises two groups of first side heating mechanisms for heating the side parts of the strip steel, and the two groups of first side heating mechanisms are arranged on the transmission side and the operation side of the furnace body respectively;

The first side heating mechanism comprises a first side magnetic induction heater arranged on the corresponding side of the furnace body and a first magnetic shielding structure for limiting the magnetic field of the first side magnetic induction heater to the corresponding side of the strip steel;

the first side electromagnetic induction heater can be driven by the movable trolley to be close to or far from the strip steel running channel so as to realize the switching of the first side electromagnetic induction heater between the working state and the standby state, and the target magnetic field action position of the first side electromagnetic induction heater can be adjusted according to specific working conditions;

the tempering heating section comprises a second longitudinal magnetic induction heating furnace section and a second soaking furnace section which are sequentially arranged along the running direction of the strip steel;

the tempering heating section further comprises a second side heating furnace section, the second side heating furnace section is arranged between the second longitudinal magnetic induction heating furnace section and the second soaking furnace section, the second side heating furnace section comprises two groups of second side heating mechanisms for heating the side parts of the strip steel, and the two groups of second side heating mechanisms are arranged on the transmission side and the operation side of the furnace body respectively.

2. The full-continuous heat treatment production system for hot rolled high strength steel according to claim 1, wherein: the quenching cooling section comprises a plurality of cooling boxes which are sequentially arranged along the running direction of the strip steel, an intermediate tension roller is arranged between two adjacent cooling boxes, a cooling mechanism is arranged in each cooling box, and the cooling mechanism comprises an aerosol cooling mechanism and/or a water spray cooling mechanism.

3. The full-continuous heat treatment production system for hot rolled high strength steel according to claim 1, wherein: the tempering cooling section comprises a tempering cooling front section and a tempering cooling rear section, wherein the tempering cooling front section is provided with a circulating gas injection cooling mechanism, and the tempering cooling rear section is provided with an air injection cooling mechanism and/or a water spray cooling mechanism.

4. The full-continuous heat treatment production system for hot rolled high strength steel according to claim 1, wherein: the product collecting unit comprises a strip steel coiling mechanism connected with the slitting shear, the strip steel coiling mechanism comprises a coiling machine, a steering pinch roll and a coil unloading vehicle, the steering pinch roll is connected with the coiling machine through a strip threading guide plate, and a bending machine is arranged on the feeding side of the steering pinch roll.

5. The full-continuous heat treatment production system for hot rolled high strength steel according to claim 4, wherein: at least one auxiliary press roller is arranged around a winding drum of the coiling machine, the axial direction of the auxiliary press roller is parallel to the axial direction of the winding drum, and the auxiliary press roller is provided with an auxiliary press roller driving unit so as to have a working position in rolling contact with the steel coil and a waiting position far away from the steel coil.

6. A heat treatment method for hot rolled high strength steel, characterized in that the hot rolled high strength steel is produced by the full continuous heat treatment production system according to any one of claims 1 to 5, wherein,

when the steel material is quenched, the steel material is rapidly heated to 750-1200 ℃ at a speed of 15-30 ℃/s, and is kept for 2-8 minutes, so that the austenitic structure of the steel material with the target form is obtained; cooling the quenched and heated steel material to a target quenching final cooling temperature by adopting a multi-stage quenching cooling mode so as to obtain a quenched martensitic structure in a target form;