Thin-gauge high-strength steel quenching plate shape control system

Abstract

The utility model discloses a quenching plate shape control system for thin high-strength steel. Comprising a quenching unit, a belt temperature straightening unit and a tempering device which are sequentially connected and arranged in the running direction of steel materials, the belt temperature straightening unit comprises a belt temperature straightening device and two tension roller sets used for tensioning the steel materials, and the two tension roller sets are arranged at the feeding end and the discharging end of the belt temperature straightening device respectively. The strip shape control of the thin high-strength steel can be realized, the deformation resistance in the straightening process of the high-strength steel can be reduced by the strip temperature straightening device, the load borne by a transmission system of the straightening device can be reduced, meanwhile, the yield strength of the strip steel can be reduced by the strip temperature straightening device, the straightening plastic deformation rate is higher, the stress can be fully released, and the strip shape can be improved; the tension roller sets are arranged at the two ends of the belt temperature straightening device to tension the strip steel, the straightening plastic deformation rate of the high-strength steel can be further increased through deviation of a neutral layer of the strip steel, and the plate shape is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high-strength steel production, in particular to a quenching shape control system for thin-specification high-strength steel plates. Background Art

[0002] For industries such as construction machinery and automobiles, realizing the high-strengthening and thin-specification of steel can save a large amount of energy costs through lightweighting, achieve energy conservation and emission reduction, improve the safety performance of construction machinery and automobiles, and extend their service life. Therefore, the demand for ultra-high-strength steel, wear-resistant steel, protective steel, etc. increases year by year, and the market demand for thin-specification high-strength steel of 4 mm and below is relatively large. The market also puts forward higher and higher requirements for the quality and output of GPa-level thin-specification high-strength steel.

[0003] During the continuous heat treatment process of high-strength steel, since the process speed is limited by the in-furnace time and the quenching process speed of the strip steel out of the furnace for quenching and cooling is constant, compared with the traditional single-plate heat treatment process, the controllable means for the quenching shape of the continuous heat treatment process are only parameters such as the quenching water ratio and nozzle flow rate, and the shape control is difficult. In addition, the thin-specification high-strength strip steel itself has a small stiffness but a large elastic modulus, and the existing roller quenching machine in the heat treatment process is not sufficient to suppress the deformation occurring during quenching and cooling. Therefore, the shape control during the quenching and cooling process is the biggest technical difficulty in the production process of thin-specification high-strength steel. Summary of the Utility Model

[0004] In order to solve the above problems, the utility model provides a quenching shape control system for thin-specification high-strength steel plates, which includes a quenching unit, a warm-straightening unit and a tempering device arranged in sequence along the running direction of the steel material. The warm-straightening unit includes a warm-straightening device and two groups of tension roller groups for tensioning the steel material. The two groups of tension roller groups are respectively arranged at the feeding end and the discharging end of the warm-straightening device.

[0005] Further, each tension roller group includes at least two tension rollers, and the distance between adjacent tension rollers is adjustable.

[0006] Further, the outer side of the tension roller is coated with a high-temperature resistant protective layer.

[0007] Further, the number of the tension rollers is two, and the two tension rollers are arranged in a vertical dislocation manner.

[0008] Further, a shape detection unit is also arranged at the discharging end of the warm-straightening device.

[0009] Further, the quenching unit includes a quenching heating device and a quenching cooling device arranged in sequence along the running direction of the steel material.

[0010] Further, the quenching cooling device is a roller quenching machine.

[0011] Furthermore, a temperature detection unit is provided at the discharge end of the quenching unit.

[0012] Due to the adoption of the above technical solutions, the present utility model has at least the following beneficial effects compared with the prior art:

[0013] The quenching plate shape control system provided by the present utility model can achieve the plate shape control of thin-gauge high-strength steel. The warm straightening device can reduce the deformation resistance during the straightening process of high-strength steel, reduce the load on the transmission system of the straightening device. At the same time, warm straightening can reduce the yield strength of the strip steel, and the straightening plastic deformation rate is higher, which can fully release stress and improve the plate shape. Tension roller groups are arranged at both ends of the warm straightening device to tension the strip steel, and the straightening plastic deformation rate of high-strength steel can be further improved through the offset of the neutral layer of the strip steel, thereby improving the plate shape. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic structural diagram of the thin-gauge high-strength steel quenching plate shape control system provided by the present utility model.

[0016] 1 - Quenching heating device; 2 - Quenching cooling device; 3 - Temperature detection unit; 4 - First tension roller group; 41 - Tension roller; 5 - Warm straightening device; 51 - Straightening roller; 6 - Plate shape detection unit; 7 - Second tension roller group; 8 - Tempering device; 9 - Strip steel. Detailed Embodiments

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present utility model. In the drawings, for clear visibility, the dimensions and relative dimensions of some parts may be enlarged.

[0018] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connection" and "coupling" shall be interpreted in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0019] In the description of the present utility model, the orientation or positional relationships such as "upper", "lower", "left", "right", "front", "rear", "center", "horizontal", "vertical", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present utility model.

[0020] In addition, in the description of the present utility model, the terms "first" and "second" are only used for distinction in description, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In addition, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0021] As shown in the Figure 1 drawings, the present utility model provides a quenching shape control system for thin - gauge high - strength steel, which includes a quenching unit, a warm - straightening unit, and a tempering device 8 arranged in sequence along the running direction of the steel material. The warm - straightening unit includes a warm - straightening device 5 and two groups of tension roller sets for tensioning the steel material. The two groups of tension roller sets are respectively arranged at the feeding end and the discharging end of the warm - straightening device 5.

[0022] Specifically, this application is applicable to the continuous heat treatment production of GPa - level thin - gauge high - strength steel, and can realize the quenching shape control of thin - gauge high - strength steel. The strip steel 9 is successively passed through the quenching unit, the warm - straightening unit, and the tempering device 8 to complete the heat treatment of the strip steel. In this embodiment, the tension roller set at the feeding end of the warm - straightening device 5 is denoted as the first tension roller set 4, and the tension roller set at the discharging end of the warm - straightening device 5 is denoted as the second tension roller set 7. The first tension roller set 4 and the second tension roller set 7 can provide tension for the strip steel 9 entering the warm - straightening device 5, can significantly improve the plastic deformation rate of the strip steel, improve the shape, and at the same time keep the maximum elongation rate at a relatively low level, avoiding surface cracking of the strip steel during the straightening process.

[0023] Optimized implementation method. The warm-strip straightening device 5 is used to control the shape value of the strip steel after quenching and cooling within a set range. The warm-strip straightening device 5 includes a number of straightening rolls 51, which are distributed in two rows, upper and lower. A strip steel movement channel is formed between the upper row of straightening rolls and the lower row of straightening rolls. The strip steel 9 passes between the upper and lower straightening rolls. The straightening rolls 51 are connected to a gear housing, and a motor drives the gears on the gear housing to rotate, thereby driving the straightening rolls 51 to rotate. A speed reducer is also provided at the output end of the motor.

[0024] Preferably, in this embodiment, the straightening rolls are 7 to 11 rolls, with a roll diameter of 20 to 80 mm; the roll spacing is 80 to 160 mm; the warm-roll straightening method with large tension is adopted. During the straightening process, the unit tension of the strip steel is 10 to 100 MPa, the strip steel temperature is 150 to 400 °C, and the straightening rolls adopt single drive and single control. The outermost layer of the straightening rolls is made of high-temperature resistant materials, such as high-temperature resistant rubber or silica gel. The temperature of the strip steel after quenching and cooling is 150 to 400 °C. Warm-strip straightening at 150 to 400 °C can reduce the deformation resistance during the straightening of high-strength steel, reduce the load on the transmission system of the straightening machine. At the same time, warm-strip straightening can reduce the yield strength of the strip steel. Under the same straightening parameters, the straightening plastic deformation rate is higher, the stress can be fully released, and the shape of the strip can be improved.

[0025] Optimized implementation method. The first tension roll group 4 and the second tension roll group 7 jointly establish the straightening tension required for the warm-strip straightening device 5. The structures of the first tension roll group 4 and the second tension roll group 7 are the same. Taking the first tension roll group 4 as an example for description. The first tension roll group 4 includes at least two tension rolls 41, and the spacing between adjacent tension rolls 41 is adjustable, so as to adjust the tension value of the strip steel 9 to meet the strip steel straightening requirements. When warm-strip straightening, tension rolls are used at the same time. By offsetting the neutral layer of the strip steel, the maximum surface elongation rate of the strip steel can be reduced, preventing cracks from appearing on the surface of the strip steel during the straightening process. At the same time, it can also achieve a straightening plastic deformation rate of 100% for thin-gauge high-strength steel, and improve the shape of the strip to the greatest extent.

[0026] Of course, in some embodiments, the structure of the second tension roll group 7 is different from that of the first tension roll group 4.

[0027] Optimized implementation method. The temperature of the strip steel 9 coming out of the quenching unit is 150 to 400 °C. The outside of the tension roll 41 is coated with a high-temperature resistant protective layer, which can withstand high temperatures below 400 °C. The protective layer can be made of high-temperature resistant silica gel or high-temperature resistant rubber. On the one hand, it can withstand the high temperature of the strip steel, and on the other hand, it can make flexible contact with the strip steel to avoid damage to the surface of the strip steel.

[0028] In this embodiment, the number of the tension rollers 41 is two, and the two tension rollers 41 are arranged in a vertical dislocation manner. The strip steel 9 sequentially passes around the two tension rollers 41 and then enters the hot leveling device 5. The distance and angle between the two tension rollers are adjustable. The tension rollers are driven by a motor and a speed reducer.

[0029] Preferably, the first tension roller group 7 and the second tension roller group 4 are flush, and the height is adapted to the strip steel movement channel of the hot leveling device.

[0030] In an optimized implementation manner, a shape detection unit 6 is further provided at the discharging end of the hot leveling device 5. The shape detection unit 6 is preferably a laser scanning type shape meter, which can measure the flatness of the surface of the straightened strip steel and determine whether the shape value is within the set range. The shape detection unit 6 is located between the hot leveling device 5 and the second tension roller group 7.

[0031] In an optimized implementation manner, the shape control system further includes a control unit. The shape detection unit 6 is connected to the control unit. The shape detection unit 6 can feed back the measurement result to the control unit. The hot leveling device can adjust the leveling process parameters in real time according to the measurement result to realize the closed-loop control of the shape value.

[0032] In an optimized implementation manner, the quenching unit includes a quenching heating device 1 and a quenching cooling device 2 arranged in sequence along the running direction of the steel material. The quenching heating device 1 uses induction heating or radiant tube heating to heat the continuously running strip steel 9 to achieve complete austenitization of the microstructure of the steel. The quenching heating device is preferably an electromagnetic induction heater. The quenching cooling device 2 is used to cool the heated strip steel 9.

[0033] Preferably, the quenching heating device heats the strip steel at a rate of 10 - 80 °C / s to 950 - 1050 °C and holds it for 1 - 4 minutes to achieve complete austenitization of the microstructure of the steel.

[0034] Preferably, the quenching cooling device 2 is preferably a roll press quenching machine, which uses high-hydrogen cooling or full-hydrogen cooling to cool the continuously running strip steel to 150 - 400 °C, and the microstructure of the steel changes to martensite. The roll press quenching machine includes an upper roll group and a lower roll group. The position of the upper roll group is adjustable. The upper roll group can be pressed down. Each upper pressure roll on the operating side and the driving side is respectively equipped with a servo hydraulic cylinder to realize the control of the pressing position and suppress the deformation of the strip steel 9 during cooling. The final quenching temperature is flexibly controlled at 150 - 400 °C. While realizing complete martensite transformation, the thermal stress generated by the maximum temperature drop is reduced to the greatest extent, which is beneficial to preventing the deterioration of the shape.

[0035] Optimized implementation mode, a temperature detection unit 3 is provided at the discharge end of the quenching unit. The temperature detection unit is arranged between the quenching cooling device 2 and the first tension roll group. The temperature detection unit 3 is preferably a scanning high-precision plate temperature meter, which measures the temperature of the plate surface after quenching and cooling.

[0036] Preferably, the plate temperature meter is connected to the control unit, and can feed back the measurement result to the control unit. The quenching cooling device 2 adjusts the cooling parameters in real time according to the measurement result to achieve closed-loop control of the plate temperature.

[0037] Optimized implementation mode, the tempering device 8 adopts induction heating or radiation heating method to temper the strip steel after temperature-holding straightening, so as to obtain a uniform tempered martensite structure and achieve the best strength and toughness matching of the strip steel.

[0038] Meanwhile, the content not detailedly described in this specification belongs to the prior art well-known to those skilled in the art.

[0039] Those skilled in the art of this technology should understand that the present utility model can be implemented in many other specific forms without departing from the spirit and scope of the present utility model. Although the embodiments of the present utility model have been described, it should be understood that the present utility model should not be limited to these embodiments. Those skilled in the art of this technology can make changes and modifications within the spirit and scope of the present utility model as defined by the appended claims.

Claims

1. A thin gauge high strength steel quenching plate shape control system, characterized in that: It comprises a quenching unit, a temperature straightening unit and a tempering device which are arranged in sequence along the running direction of the steel material. The temperature straightening unit comprises a temperature straightening device and two groups of tension rollers for tensioning the steel material. The two groups of tension rollers are respectively arranged at the feeding end and the discharging end of the temperature straightening device.

2. The thin gauge high strength steel quenching plate shape control system according to claim 1 is characterized in that: The tension roller group includes at least two tension rollers, and the distance between the tension rollers is adjustable.

3. The thin gauge high strength steel quenching plate shape control system according to claim 2, characterized in that: The outer side of the tension roller is coated with a high temperature resistant protective layer.

4. The thin gauge high strength steel quenching plate shape control system according to claim 2, characterized in that: The number of the tension rollers in each tension roller group is two, and the two tension rollers are staggered in the vertical direction.

5. The thin gauge high strength steel quenching plate shape control system according to claim 1, characterized in that: The discharge end of the temperature-straightening device is also provided with a plate shape detection unit.

6. The thin gauge high strength steel quenching plate shape control system according to claim 1, characterized in that: The quenching unit comprises a quenching heating device and a quenching cooling device which are sequentially arranged along the running direction of the steel material.

7. The thin gauge high strength steel quenching plate shape control system according to claim 6, characterized in that: The quenching and cooling device is a roller quenching machine.

8. The thin gauge high strength steel quenching plate shape control system according to claim 1, characterized in that: A temperature detection unit is provided at the discharge end of the quenching unit.

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