A method for hot rolling a high-strength steel sheet

Abstract

The application provides a high-strength steel plate hot rolling method, wherein the high-strength steel plate hot rolling method comprises a heating process, a rough rolling process and a finish rolling process, wherein in the heating process, the heating temperature and the heating time of the steel plate in a heating furnace are regulated; in the rough rolling process, the rolling parameters in the rough rolling process are adjusted; and in the finish rolling process, the rolling parameters in the finish rolling process are adjusted. The application solves the problem of unstable rolling of the high-strength steel plate in the production process in the prior art, and greatly improves the stability of the high-strength steel plate rolling and guarantees the quality of the steel plate by regulating the heating temperature and the heating time of the steel plate in the heating furnace and reasonably adjusting the rolling parameters in the rough rolling process and the rolling parameters in the finish rolling process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel rolling, in particular to a hot rolling method of high-strength steel plate. BACKGROUND

[0002] The high-strength steel plate can be used for automobile manufacturing, and the thin-gauge high-strength automobile structure pickling plate product is a recognized problem in conventional hot continuous rolling, which has problems such as large hot deformation resistance, unstable threading, easy tail throwing, and easy flying and lifting, and has high requirements on the size, shape, temperature, and surface of the steel plate. Defects such as roll marks and oxidized pitting are not allowed on the surface of the steel plate. The rolling stability problem of the thin-gauge high-strength automobile structure pickling plate not only causes direct quality loss such as folding and roll mark defects, but also affects the realization of orders and causes repeated feeding.

[0003] Therefore, how to use an effective method to improve the rolling stability of the high-strength steel plate and ensure stable production of the steel plate and improve the production efficiency is a technical problem to be solved. SUMMARY

[0004] The purpose of the present application is to provide a hot rolling method of high-strength steel plate, which can solve the problem of unstable rolling of high-strength steel plate in the production process caused by factors such as uneven heating of the steel plate, insufficient solid solution of micro-alloying, change of rough rolling shape, excessive rough rolling temperature drop, poor width consistency, thick intermediate billet thickness of the steel plate, poor coil shape of the coil box, low head temperature of the finished rolling steel plate, load distribution strategy, loop control strategy, roll shifting strategy, and finishing rolling centering strategy in the prior art. The present application improves the uniformity of the steel plate temperature by standardizing the temperature and time requirements of each section of the heating furnace in the heating process to promote the full solid solution of micro-alloying elements; further improves the intermediate billet shape of the rough rolling steel plate, reduces the rough rolling temperature drop, and improves the width accuracy by standardizing the rolling mode of the rough rolling area, the intermediate billet thickness of the steel plate, the side guide plate centering strategy, and the vertical roll control strategy; improves the intermediate coil shape by adjusting the coil box speed in the finishing rolling process; and improves the rolling stability of the steel plate and ensures the quality of the steel plate by performing the head passing function of the finishing descaling device and dust suppression water device, optimizing the load distribution of the rolling mill, the loop control strategy, the roll shifting strategy, and the finishing rolling area centering strategy.

[0005] Specifically, the present application adopts the following technical solutions:

[0006] The embodiment of the present application provides a hot rolling method of high-strength steel plate, which comprises a heating process, a rough rolling process, and a finishing rolling process, wherein in the heating process, the heating temperature and the discharge temperature of the steel plate in the heating furnace are determined according to the width of the steel plate, and the heating time of the steel plate in the heating furnace is determined according to the charging temperature of the steel plate.

[0007] In the rough rolling process, the first rough rolling side guide plate and the second rough rolling side guide plate of the rough rolling mill train control the static centering of the steel plate according to a preset offset; when the steel plate is rough rolled, the steel plate is controlled to pass through the side press, the steel plate is rolled once by the first rolling mill of the rough rolling mill train, and the steel plate is rolled five times by the second rolling mill of the rough rolling mill train; when the second rolling mill rolls the steel plate for the first time and the third time, the reduction of the edger roller of the second rolling mill is controlled to be less than or equal to 55 mm, so as to complete the rough rolling process of the steel plate.

[0008] In the finishing rolling process, the bite speed of the coiler box biting into the steel plate is controlled to be 3.2 m / s, and the coiling speed of the coiler box when coiling the steel plate is controlled to be 4 m / s; the offset of the coiler box inlet side guide plate is adjusted, and the opening degree of the first stabilizer and the second stabilizer of the coiler box is determined according to the production state of the steel plate in the coiler box; the opening degree of the flying shear side guide plate is adjusted; the head of the steel plate is controlled to pass through the function of the phosphorus removal device and the dust suppression water device of the finishing rolling mill train; the rolling mill load of the first rolling mill to the sixth rolling mill of the finishing rolling mill train is adjusted; the angles of the third loop, the fourth loop and the fifth loop of the finishing rolling mill train are controlled to be preset angles; the roll shifting value of each rolling mill of the finishing rolling mill train is set; when the head of the steel plate reaches the edger roller of the first rolling mill of the finishing rolling mill train, the pressure of the edger roller is controlled to be 5 tons, and the offset of the edger roller is controlled to be -15 mm; the opening degree of the side guide plate of the finishing rolling mill train is adjusted.

[0009] In some embodiments of the present application, based on the foregoing scheme, the heating temperature and the discharge temperature of the steel plate in the heating furnace are determined according to the width of the steel plate, which includes: if the width of the steel plate is less than 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1250℃-1260℃, the soaking section temperature of the heating furnace is controlled to be 1255℃, and the discharge temperature of the steel plate is controlled to be 1250℃-1260℃; if the width of the steel plate is greater than or equal to 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1260℃-1270℃, the soaking section temperature of the heating furnace is controlled to be 1265℃, and the discharge temperature of the steel plate is controlled to be 1260℃-1270℃.

[0010] In some embodiments of the present application, based on the foregoing scheme, the determination of the heating time of the steel plate in the heating furnace according to the entry temperature of the steel plate comprises: if the entry temperature of the steel plate is less than 300℃, controlling the heating time of the steel plate in the heating furnace to be 180min; if the entry temperature of the steel plate is greater than or equal to 300℃ and less than or equal to 500℃, controlling the heating time of the steel plate in the heating furnace to be 170min; if the entry temperature of the steel plate is greater than 500℃, controlling the heating time of the steel plate in the heating furnace to be 160min.

[0011] In some embodiments of the present application, based on the foregoing scheme, the preset offset is 50mm.

[0012] In some embodiments of the present application, based on the foregoing scheme, the adjustment of the offset of the entry side guide plate of the coil box comprises: determining the opening degree of the first stabilizer and the second stabilizer of the coil box according to the production state of the steel plate in the coil box.

[0013] When the head of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 50mm; when the middle part of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 20mm; when the tail of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 20mm.

[0014] When the head of the steel plate reaches the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 120mm; when the steel plate is being coiled in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 120mm; when the steel plate is completed coiling in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be -20mm; when the steel plate is being uncoiled in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 80mm; when the head of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer is controlled to be 120mm; when the middle part of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer is controlled to be 40mm.

[0015] In some embodiments of the present application, based on the foregoing scheme, the adjustment of the opening degree of the flying shear side guide plate comprises: when the head of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 30mm; when the middle part of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be -10mm; when the tail of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 0mm.

[0016] In some embodiments of the present application, based on the foregoing scheme, the adjustment of the rolling mill load of the first to sixth rolling mills of the finishing rolling mill train comprises: controlling the rolling mill load of the first rolling mill of the finishing rolling mill train to be 50kw, and controlling the rolling mill load of the second, third, fourth, fifth and sixth rolling mills to be 42kw-20kw.

[0017] In some embodiments of the present application, based on the foregoing scheme, the preset angle is 16°-18°

[0018] In some embodiments of the present application, based on the foregoing scheme, the setting of the roll shifting value of the roll shifting of each rolling mill of the finishing rolling mill train comprises: controlling the roll shifting value of the roll shifting of the first rolling mill of the finishing rolling mill train to be -10mm-50mm; controlling the roll shifting value of the roll shifting of the second rolling mill of the finishing rolling mill train to be 10mm-40mm; controlling the roll shifting value of the roll shifting of the third rolling mill of the finishing rolling mill train to be 0mm-40mm; controlling the roll shifting value of the roll shifting of the fourth rolling mill of the finishing rolling mill train to be 20mm-60mm; controlling the roll shifting value of the roll shifting of the fifth rolling mill of the finishing rolling mill train to be 10mm-50mm; and determining the roll shifting value of the roll shifting of the sixth rolling mill of the finishing rolling mill train according to the plate shape rolling data of the steel plate of the first to fifth rolling mills of the finishing rolling mill train.

[0019] In some embodiments of the present application, based on the foregoing scheme, the adjustment of the side guide opening degree of the finishing rolling mill train comprises: when the head and middle part of the steel plate reaches the first finishing side guide of the finishing rolling mill train, controlling the opening degree of the first finishing side guide to be 20; when the head and middle part of the steel plate reaches the second finishing side guide of the finishing rolling mill train, controlling the opening degree of the second finishing side guide to be 20; when the head and middle part of the steel plate reaches the third finishing side guide of the finishing rolling mill train, controlling the opening degree of the third finishing side guide to be 30;

[0020] when the tail of the steel plate reaches the fourth finishing side guide of the finishing rolling mill train, controlling the opening degree of the fourth finishing side guide to be 40; when the head and middle part of the steel plate reaches the fifth finishing side guide of the finishing rolling mill train, controlling the opening degree of the fifth finishing side guide to be 30, and when the tail of the steel plate reaches the fifth finishing side guide of the finishing rolling mill train, controlling the opening degree of the fifth finishing side guide to be 60.

[0021] From the above technical solutions, the present application has at least the following advantages and positive effects:

[0022] The application can solve the problem of unstable rolling of high-strength steel plates in the production process caused by uneven heating of the steel plates, insufficient solid solution of micro-alloying elements, rough rolling shape change, excessive rough rolling temperature drop, poor width consistency, thick intermediate slab thickness of the steel plates, poor coil shape of the plate coil box, low head temperature of the finished rolling steel plates, load distribution strategy, loop control strategy, roll shifting strategy, and finishing rolling centering strategy, etc. in the prior art. The application improves the uniformity of the steel plate temperature by standardizing the temperature and time requirements of each section of the heating furnace in the heating process to promote the full solid solution of micro-alloying elements. The intermediate slab shape of the rough rolling steel plates is further improved, the rough rolling temperature drop is reduced, and the width accuracy is improved by standardizing the rough rolling area rolling mode, the intermediate slab thickness of the steel plates, the side guide plate centering strategy, and the vertical roll control strategy. The intermediate coil shape is improved by adjusting the speed of the plate coil box in the finishing rolling process. The rolling stability of the steel plates is improved by performing the head passing function of the finishing descaling and dust suppression water, optimizing the rolling mill load distribution, loop control strategy, roll shifting strategy, and finishing rolling area centering strategy, etc. to ensure the quality of the steel plates. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the embodiments consistent with the present application and, together with the description, further serve to explain the principles of the present application. It is to be understood that the drawings are designed solely for purposes of illustration to be used in conjunction with the description in envisioning what is being described. These drawings, which are not a limiting factor, show:

[0024] Figure 1 A high-strength steel plate hot rolling method flow chart in an embodiment of the application is shown;

[0025] Figure 2 A plate coil box area roll system schematic diagram in an embodiment of the application is shown;

[0026] Figure 3 A finishing rolling mill area roll system schematic diagram in an embodiment of the application is shown. DETAILED DESCRIPTION

[0027] Example implementations will now be described with reference to the drawings; however, example implementations can be implemented in many different forms and should not be construed as being limited to the examples set forth herein; rather, these implementations are provided so that the application will be thorough and complete, and will fully convey the concept of example implementations to those skilled in the art.

[0028] Moreover, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the application can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the application.

[0029] The flowcharts shown in the drawings are merely illustrative and do not necessarily include all the contents and operations / steps, nor are they necessarily executed in the order described. For example, some operations / steps can be further broken down, and some operations / steps can be combined or partially combined, so the actual execution order can be changed according to actual conditions.

[0030] It should be noted that the terms "first", "second", and the like in the specification and claims of the application and the above-described drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the objects thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described.

[0031] The implementation details of the technical solutions of the embodiments of the application are described in detail as follows:

[0032] According to the present application, a high-strength steel plate hot rolling method is provided, referring to Figure 1 , the flowchart of the high-strength steel plate hot rolling method of the present application, the method comprises a heating process, a rough rolling process, a finishing rolling process, and the specific steps S1 to S3 are as follows:

[0033] Step S1, in the heating process, the heating temperature and the discharge temperature of the steel plate in the heating furnace are determined according to the width of the steel plate, and the heating time of the steel plate in the heating furnace is determined according to the entry temperature of the steel plate.

[0034] In the present application, before the steel plate is rolled, the steel plate needs to be heated in a heating furnace to improve the plasticity of the steel plate and reduce the deformation resistance. The heating furnace can generally be divided into a preheating section, a first heating section, a second heating section and a soaking section. If the temperature and time requirements of each section of the heating furnace are not standardized, the insufficient solid solution of niobium in the steel containing micro-alloying elements will cause the first heating section temperature to be too low, and the second heating section and the soaking section temperature to be too high, resulting in uneven temperature between the surface and the core of the steel plate.

[0035] The heating temperature and the discharge temperature of the steel plate in the heating furnace can be determined according to the width of the steel plate, the heating time of the steel plate in the heating furnace and the soaking time of the steel plate in the soaking section of the heating furnace are determined according to the entry temperature of the steel plate, so as to ensure the uniformity of the heating temperature of the steel plate in the heating furnace, and to ensure that the micro-alloying elements are fully solid-solved in the steel plate, so as to improve the plasticity of the steel plate and reduce the deformation resistance.

[0036] In an embodiment of the present application, the heating temperature and the discharge temperature of the steel plate in the heating furnace can be determined according to the width of the steel plate, wherein if the width of the steel plate is less than 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1250℃-1260℃, the soaking section temperature of the heating furnace is controlled to be 1255℃, and the discharge temperature of the steel plate is controlled to be 1250℃-1260℃.

[0037] If the width of the steel plate is greater than or equal to 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1260℃-1270℃, the soaking section temperature of the heating furnace is controlled to be 1265℃, and the discharge temperature of the steel plate is controlled to be 1260℃-1270℃.

[0038] In an embodiment of the present application, the heating time of the steel plate in the heating furnace can be determined according to the entry temperature of the steel plate, wherein if the entry temperature of the steel plate is less than 300℃, the heating time of the steel plate in the heating furnace is controlled to be 180 min; if the entry temperature of the steel plate is greater than or equal to 300℃ and less than or equal to 500℃, the heating time of the steel plate in the heating furnace is controlled to be 170 min; if the entry temperature of the steel plate is greater than 500℃, the heating time of the steel plate in the heating furnace is controlled to be 160 min, and the soaking time of the soaking section of the heating furnace can be controlled to be 30 min.

[0039] In step S2, in the rough rolling process, the first rough rolling side guide plate and the second rough rolling side guide plate of the rough rolling mill group are controlled to statically center the steel plate according to a preset offset; when the steel plate is rough rolled, the steel plate is controlled to pass through the side press, the steel plate is rolled once by the first rolling mill of the rough rolling mill group, and the steel plate is rolled five times by the second rolling mill of the rough rolling mill group; when the second rolling mill rolls the steel plate for the first time and the third time, the reduction amount of the edger roll of the second rolling mill is controlled to be less than or equal to 55 mm, so as to complete the rough rolling process of the steel plate.

[0040] In an embodiment of the present application, the preset offset is 50 mm.

[0041] In the present application, after the steel plate is heated, the steel plate is subjected to rough rolling treatment. In the rough rolling sequence, the first rough rolling side guide plate and the second rough rolling side guide plate of the rough rolling mill train control the static centering of the steel plate according to a preset offset (the preset offset can be 50 mm, or other offsets, which are not particularly limited in the present application, and can be adjusted according to actual needs), the first rough rolling side guide plate is installed before the first rolling mill of the rough rolling mill train, and the second rough rolling side guide plate is installed before the second rolling mill of the rough rolling mill train, for centering the steel plate to ensure that the steel plate can smoothly enter the rough rolling mill for rolling.

[0042] In the present application, when the steel plate is subjected to rough rolling, the rough rolling mode adopts a 0+1+5 mode, the steel plate is controlled to pass through the side press (and when the steel plate passes through the side press in the rough rolling process, the side press is controlled not to side press the steel plate), the steel plate is rolled once by the first rolling mill of the rough rolling mill train, and the steel plate is rolled five times by the second rolling mill of the rough rolling mill train; when the second rolling mill rolls the steel plate for the first time and the third time, the second rolling mill is controlled to have a stand roll reduction of less than or equal to 55 mm to reduce the head-to-tail width deviation of the steel plate and improve the consistency of the width of the steel plate, thereby completing the rough rolling process of the steel plate.

[0043] In step S3, in the finishing rolling process, the bite speed of the coil box when biting the steel plate is controlled to be 3.2 m / s, the coiling speed of the coil box when coiling the steel plate is controlled to be 4 m / s; the offset of the inlet side guide plate of the coil box is adjusted, the opening degree of the first stabilizer and the second stabilizer of the coil box is determined according to the production state of the steel plate in the coil box; the opening degree of the flying shear side guide plate is adjusted; the head passing function of the steel plate is performed by the phosphorus removal device and the dust suppression water device of the finishing mill train; the rolling load of the first rolling mill to the sixth rolling mill of the finishing mill train is adjusted; the angles of the third loop, the fourth loop and the fifth loop of the finishing mill train are controlled to be preset angles; the roll shifting value of each rolling mill of the finishing mill train is set; when the head of the steel plate reaches the stand roll of the first rolling mill of the finishing mill train, the pressure of the stand roll is controlled to be 5 tons, and the offset of the stand roll is controlled to be -15 mm; the opening degree of the side guide plate of the finishing mill train is adjusted.

[0044] In an embodiment of the present application, the preset angle is 16°-18°.

[0045] In the present application, after rough rolling of the steel plate is completed, the steel plate can be coiled by a coil box, the coil box is installed at the entrance area of the finishing mill, used for coreless coiling of the intermediate blank from the rough rolled steel plate, and then uncoiling to enter the finishing mill. In order to ensure that the steel plate can be smoothly coiled by the coil box, when the coil box bites the steel plate, the bite speed of the coil box can be controlled to be 3.2 m / s, when the steel plate starts to be coiled, the coiling speed of the coil box when coiling the steel plate is controlled to be 4 m / s, by reducing the bite speed and the coiling speed of the coil box, the intermediate coil shape of the steel plate is improved, so that the intermediate blank of the steel plate can be coiled in the coil box.

[0046] Referring to Figure 2 , the coil box entrance side is provided with a coil box entrance side guide plate 201, which is used for centering the steel plate to ensure that the steel plate can smoothly enter the coil box for coiling, when the steel plate reaches the coil box entrance side guide plate 201, the offset of the coil box entrance side guide plate 201 can be adjusted. The coil box area is also provided with a first stabilizer 202 and a second stabilizer 203, the opening degree of the first stabilizer 202 and the second stabilizer 203 of the coil box can be determined according to the production state of the steel plate in the coil box.

[0047] In an embodiment of the present application, the offset of the coil box entrance side guide plate can be adjusted, and the opening degree of the first stabilizer and the second stabilizer of the coil box can be determined according to the production state of the steel plate in the coil box, wherein when the head of the steel plate reaches the entrance side guide plate of the coil box, the offset of the entrance side guide plate is controlled to be 50 mm, when the middle part of the steel plate reaches the entrance side guide plate of the coil box, the offset of the entrance side guide plate is controlled to be 20 mm, and when the tail of the steel plate reaches the entrance side guide plate of the coil box, the offset of the entrance side guide plate is controlled to be 20 mm.

[0048] When the head of the steel plate reaches the coil box, the opening degree of the first stabilizer of the coil box can be controlled to be 120 mm; when the steel plate is coiled in the coil box, the opening degree of the first stabilizer of the coil box can be controlled to be 120 mm; when the steel plate is coiled in the coil box, the opening degree of the first stabilizer of the coil box can be controlled to be -20 mm; when the steel plate is uncoiled in the coil box, the opening degree of the first stabilizer of the coil box can be controlled to be 80 mm; when the head of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer can be controlled to be 120 mm; when the middle part of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer can be controlled to be 40 mm.

[0049] The flying shear is arranged between the plate rolling box and the finishing rolling unit, and is used for shearing irregular head and tail of the steel plate in operation. The steel plate needs to pass through the flying shear side guide plate before the flying shear before operation, and the flying shear side guide plate can be used for centering and operating the steel plate to enter the flying shear for shearing. When the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate can be adjusted to ensure that the steel plate can smoothly enter the flying shear for shearing.

[0050] In an embodiment of the present application, the opening degree of the flying shear side guide plate can be adjusted. When the head of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate can be controlled to be 30 mm; when the middle part of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate can be controlled to be -10 mm; and when the tail of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate can be controlled to be 0 mm.

[0051] In the present application, with reference to Figure 3 , the finishing rolling unit can include a vertical roll 307 before the first rolling mill, the first rolling mill 301, the second rolling mill 302, the third rolling mill 303, the fourth rolling mill 304, the fifth rolling mill 305, and the sixth rolling mill 306. When the steel plate passes through the finishing rolling unit, the finishing rolling unit is controlled to perform a let-through function on the head of the steel plate by the finishing descaling device and the dust suppression water device. That is, when the head of the steel plate passes through the finishing descaling device, the finishing descaling device is controlled to open only one descaling header to perform descaling treatment on the head of the steel plate. When the head of the steel plate passes through the dust suppression water device, the dust suppression water device is controlled not to spray dust suppression water on the head of the steel plate, so as to improve the temperature of the head of the steel plate.

[0052] With reference to Figure 3When the steel plate is subjected to finish rolling treatment in the finish rolling mill train, the rolling mill load of the first rolling mill 301 to the sixth rolling mill 306 of the finish rolling mill train can be adjusted to adjust the rolling force of the rolling mills of the finish rolling mill train, so as to avoid problems such as rolling mill vibration, roll jumping and damage of the rolling mill oxidation film during rolling of the finish rolling mill train, thereby affecting the plate shape of the steel plate. When the steel plate is subjected to finish rolling treatment, the angles of the third loop, the fourth loop and the fifth loop of the finish rolling mill train can be preset angles, and the tension of the steel plate is adjusted to ensure that the tension of the steel plate is adapted to the thickness of the steel plate. It should be noted that the third loop is the loop between the third rolling mill 303 and the fourth rolling mill 304, the fourth loop is the loop between the fourth rolling mill 304 and the fifth rolling mill 305, the fifth loop is the loop between the fifth rolling mill 305 and the sixth rolling mill 306, and the preset angle can be 16°-18°, and the preset angle can also be other angles, which is not particularly limited in the present application, and can be adjusted according to actual needs.

[0053] In an embodiment of the present application, the rolling mill load of the first rolling mill to the sixth rolling mill of the finish rolling mill train can be adjusted, wherein the rolling mill load of the first rolling mill of the finish rolling mill train can be controlled to be 50kw, and the rolling mill load of the second rolling mill, the third rolling mill, the fourth rolling mill, the fifth rolling mill and the sixth rolling mill can be controlled to be 42kw-20kw. It should be noted that the rolling mill load of the first rolling mill to the sixth rolling mill of the finish rolling mill train is not limited in the present application, and can be adjusted according to actual needs.

[0054] When the steel plate is subjected to finish rolling treatment in the finish rolling mill train, the plate crown is controlled by the roll shifting of each rolling mill of the finish rolling mill train. In order to ensure the plate shape of the steel plate, the roll shifting value range of the roll shifting can be specified according to the rolling data, so as to prevent the plate shape from being poor due to too large roll shifting change of a certain rolling mill stand, and the roll shifting value of the roll shifting of each rolling mill of the finish rolling mill train can be manually set to avoid accidents such as middle wave of the steel plate. The stability of the plate shape control of the steel plate is greatly improved.

[0055] In an embodiment of the present application, the roll shifting value of the roll shifting of each rolling mill of the finish rolling mill train is set, wherein the roll shifting value of the roll shifting of the first rolling mill of the finish rolling mill train is controlled to be-10mm-50mm; the roll shifting value of the roll shifting of the second rolling mill of the finish rolling mill train is controlled to be 10mm-40mm; the roll shifting value of the roll shifting of the third rolling mill of the finish rolling mill train is controlled to be 0mm-40mm; the roll shifting value of the roll shifting of the fourth rolling mill of the finish rolling mill train is controlled to be 20mm-60mm; the roll shifting value of the roll shifting of the fifth rolling mill of the finish rolling mill train is controlled to be 10mm-50mm; and the roll shifting value of the roll shifting of the sixth rolling mill of the finish rolling mill train is determined according to the plate shape rolling data of the steel plate of the first rolling mill to the fifth rolling mill of the finish rolling mill train.

[0056] It is to be noted that the sixth rolling mill of the finishing rolling mill group plays a final adjustment role on the shape of the steel plate, and therefore the roll shifting value of the sixth rolling mill of the finishing rolling mill group needs to be determined according to the shape rolling data of the steel plate rolled by the first to fifth rolling mills of the finishing rolling mill group. If the steel plate has a shape problem after being rolled by the first to fifth rolling mills of the finishing rolling mill group, the sixth rolling mill can be used to adjust the shape of the steel plate to ensure the final shape of the steel plate.

[0057] When the steel plate is subjected to the finishing rolling process of the finishing rolling mill group, the steel plate first passes through the vertical roll of the first rolling mill of the finishing rolling mill group, and then passes through the first to sixth rolling mills of the finishing rolling mill group in sequence. When the head of the steel plate reaches the vertical roll of the first rolling mill of the finishing rolling mill group, the pressure of the vertical roll is controlled to be 5 tons, and the offset of the vertical roll is controlled to be -15 mm, so as to ensure that the steel plate can smoothly enter the finishing rolling mill group for the finishing rolling process. When the steel plate reaches the side guide plate of the finishing rolling mill group, the opening degree of the side guide plate of the finishing rolling mill group is adjusted.

[0058] In an embodiment of the present application, the opening degree of the side guide plate of the finishing rolling mill group is adjusted, wherein when the steel plate reaches the first finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the first finishing rolling side guide plate can be controlled to be 20; when the steel plate reaches the second finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the second finishing rolling side guide plate can be controlled to be 20; and when the steel plate reaches the third finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the third finishing rolling side guide plate can be controlled to be 30.

[0059] When the head and the middle part of the steel plate reach the fourth finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the fourth finishing rolling side guide plate can be controlled to be 30; when the tail of the steel plate reaches the fourth finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the fourth finishing rolling side guide plate can be controlled to be 40; when the head and the middle part of the steel plate reach the fifth finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the fifth finishing rolling side guide plate can be controlled to be 30; and when the tail of the steel plate reaches the fifth finishing rolling side guide plate of the finishing rolling mill group, the opening degree of the fifth finishing rolling side guide plate can be controlled to be 60.

[0060] In the present application, the final product of the steel plate can be a high-strength automobile structure pickling plate.

[0061] The specific embodiments of the present application will be further illustrated by specific examples, but the specific embodiments of the present application are not limited to the following examples.

[0062] In one specific embodiment of the present application, taking the production of a steel plate with a yield strength of 420 MPa and a specification of 2.0 mm*1258 mm (thickness*width) in a 2160 production line as an example.

[0063] In the heating process, the first heating section temperature of the heating furnace is controlled to be 1121℃, the second heating section temperature is controlled to be 1265℃, the soaking section temperature is controlled to be 1258℃, the soaking section heating time is controlled to be 47 minutes, and the total in-furnace heating time is controlled to be 202 minutes.

[0064] In the rough rolling process, the first side guide plate and the second side guide plate of the rough rolling mill group are controlled to perform static centering on the steel plate according to a preset offset of 50 mm, so as to improve the intermediate blank centering property of the steel plate and improve the intermediate blank flatness of the steel plate. The rough rolling mode is 0+1+5 mode. When the steel plate is rough rolled, the steel plate is controlled to be bypassed by the side press, the steel plate is rolled by one pass by the first rolling mill of the rough rolling mill group, the steel plate is rolled by five passes by the second rolling mill of the rough rolling mill group, and the thickness of the steel plate is controlled to be 26 mm. When the second rolling mill rolls the steel plate by the first pass and the third pass, the reduction of the vertical roll of the second rolling mill is controlled to be less than or equal to 55 mm, so as to complete the rough rolling process of the steel plate.

[0065] In the finishing rolling process, the bite speed of the coil box when biting the steel plate is controlled to be 3.2 m / s, and the coiling speed of the coil box when coiling the steel plate is controlled to be 4 m / s. By reducing the bite speed and the coiling speed of the coil box, the intermediate coil shape of the steel plate is improved. The offset of the entry side guide plate of the coil box is adjusted: when the head of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 50 mm; when the middle of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 20 mm; and when the tail of the steel plate reaches the entry side guide plate of the coil box, the offset of the entry side guide plate is controlled to be 20 mm.

[0066] The opening degree of the first stabilizer and the second stabilizer of the coil box is determined according to the production state of the steel plate in the coil box: when the head of the steel plate reaches the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 120 mm; when the steel plate is coiled in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 120 mm; when the steel plate is coiled in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be -20 mm; when the steel plate is uncoiled in the coil box, the opening degree of the first stabilizer of the coil box is controlled to be 80 mm; when the head of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer is controlled to be 120 mm; and when the middle of the steel plate reaches the second stabilizer of the coil box, the opening degree of the second stabilizer is controlled to be 40 mm.

[0067] Adjusting the opening degree of the flying shear side guide plate: when the head of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 30 mm; when the middle of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be -10 mm; when the tail of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 0 mm.

[0068] Controlling the fine phosphorus removal device of the finishing rolling mill and the dust suppression water device between the fourth rolling mill and the sixth rolling mill of the finishing rolling mill to perform a passing function on the head of the steel plate, and increasing the temperature of the head of the steel plate; adjusting the rolling mill load of the first rolling mill to the sixth rolling mill of the finishing rolling mill: the load of the first rolling mill is fixed to 50 kw, the load of the second rolling mill to the sixth rolling mill ranges from 42 kw to 20 kw, and the load ratio is 2.5:1 to realize load advancement. The rolling mill load corresponds to the rolling force of the rolling mill, wherein the rolling force of the first rolling mill of the finishing rolling mill is 3153 tons, the rolling force of the second rolling mill of the finishing rolling mill is 2654 tons, the rolling force of the third rolling mill of the finishing rolling mill is 2277 tons, the rolling force of the fourth rolling mill of the finishing rolling mill is 1765 tons, the rolling force of the fifth rolling mill of the finishing rolling mill is 1509 tons, and the rolling force of the sixth rolling mill of the finishing rolling mill is 1213 tons.

[0069] Controlling the angle of the third loop, the fourth loop and the fifth loop of the finishing rolling mill to be 16°-18°; manually setting the roll shifting value of the roll shifting of each rolling mill of the finishing rolling mill: the roll shifting value of the first rolling mill of the finishing rolling mill is controlled to be 50 mm; the roll shifting value of the second rolling mill of the finishing rolling mill is controlled to be 35 mm; the roll shifting value of the third rolling mill of the finishing rolling mill is controlled to be 30 mm; the roll shifting value of the fourth rolling mill of the finishing rolling mill is controlled to be 50 mm; the roll shifting value of the fifth rolling mill of the finishing rolling mill is controlled to be 50 mm; the roll shifting value of the sixth rolling mill of the finishing rolling mill is controlled to be -10 mm. When the head of the steel plate reaches the vertical roll of the first rolling mill of the finishing rolling mill, the pressure of the vertical roll is controlled to be 5 tons, and the offset amount of the vertical roll is controlled to be -15 mm.

[0070] Adjusting the opening degree of the side guide plate of the finishing rolling mill: when the steel plate reaches the first side guide plate of the finishing rolling mill, the opening degree of the first side guide plate is controlled to be 20; when the steel plate reaches the second side guide plate of the finishing rolling mill, the opening degree of the second side guide plate is controlled to be 20; when the steel plate reaches the third side guide plate of the finishing rolling mill, the opening degree of the third side guide plate is controlled to be 30;

[0071] when the head and middle part of the steel plate reach the fourth side guide plate of the finishing rolling mill train, the opening degree of the fourth side guide plate is controlled to be 30, and when the tail part of the steel plate reaches the fourth side guide plate of the finishing rolling mill train, the opening degree of the fourth side guide plate is controlled to be 40;

[0072] when the head and middle part of the steel plate reach the fifth side guide plate of the finishing rolling mill train, the opening degree of the fifth side guide plate is controlled to be 30, and when the tail part of the steel plate reaches the fifth side guide plate of the finishing rolling mill train, the opening degree of the fifth side guide plate is controlled to be 60.

[0073] From the above technical solution, the present application has at least the following aspects of advantages and positive effects:

[0074] Firstly, the scheme provided by the present application can solve the problem of unstable rolling of high-strength steel plates in the production process in the prior art. The present application regulates the heating temperature and time of the steel plate in the heating furnace, reasonably adjusts the rolling parameters in the rough rolling process and the rolling parameters in the finishing rolling process, greatly improves the stability of the high-strength steel plate rolling, and ensures the quality of the steel plate.

[0075] Firstly, the scheme provided by the present application can solve the problem of unstable rolling of high-strength steel plates in the production process in the prior art. The present application regulates the heating temperature and time of the steel plate in the heating furnace, reasonably adjusts the rolling parameters in the rough rolling process and the rolling parameters in the finishing rolling process, greatly improves the stability of the high-strength steel plate rolling, and ensures the quality of the steel plate.

[0076] Secondly, the present application regulates the temperature and time requirements of each section of the heating furnace in the heating process to improve the uniformity of the steel plate temperature and promote the full solid solution of the micro-alloying elements.

[0077] Thirdly, in the rough rolling process, the present application regulates the rough rolling area rolling mode, the intermediate slab thickness of the steel plate, the side guide plate centering strategy and the vertical roll control strategy, further improves the intermediate slab shape of the rough rolling steel plate, reduces the rough rolling temperature drop and improves the width accuracy.

[0078] Fourthly, in the finishing rolling process, the present application adjusts the steel biting speed and the coiling speed of the coiling box to improve the intermediate coil shape, performs the head passing function on the finishing descaling and dust suppression water to improve the head temperature of the steel plate, optimizes the rolling mill load distribution, the loop control strategy, the roll shifting strategy and the finishing rolling area centering strategy, improves the rolling stability of the steel plate and ensures the shape and quality of the steel plate.

[0079] Fifthly, the scheme provided by the application can ensure high-quality production of the steel plate, improve the quality and production efficiency of the steel plate, increase market competitiveness and capital income, greatly reduce the scrap quantity of the steel plate and the damage quantity of the equipment, and greatly save resources and equipment maintenance funds.

[0080] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the application being indicated by the following claims.

[0081] While the application has been described with reference to several exemplary embodiments, it is to be understood that the use of other words or terms such as "preferably," "according to a preferred embodiment," "more preferably," "more preferably still," "particularly," "particularly preferred" and "most preferably" or other seemingly declarative language (e.g., because, accordingly, wherein, where, etc.), is intended to convey that the descriptive label or adjective associated with a stated feature is considered, under at least some circumstances, as an industry practice, an industry standard, a design choice, or a user preference, and is not intended (nor used) to connote or suggest that the feature so described is critical, essential, or even important to the structure or function of the application.

Claims

1. A hot rolling method of a high-strength steel sheet, characterized by, The method comprises a heating process, a rough rolling process, and a finishing rolling process, wherein In the heating process, the heating temperature and the discharge temperature of the steel plate in the heating furnace are determined according to the width of the steel plate, and the heating time of the steel plate in the heating furnace is determined according to the entry temperature of the steel plate; In the rough rolling process, the first rough rolling side guide plate and the second rough rolling side guide plate of the rough rolling mill train are controlled to statically center the steel plate according to a preset offset; when the steel plate is rough-rolled, the steel plate is controlled to pass through the side press, the steel plate is rolled once by the first rolling mill of the rough rolling mill train, and the steel plate is rolled five times by the second rolling mill of the rough rolling mill train; when the steel plate is rolled for the first time and the third time, the reduction of the edger of the second rolling mill is controlled to be less than or equal to 55 mm, so as to complete the rough rolling process of the steel plate; In the finishing rolling process, the bite speed of the coil box when biting the steel plate is controlled to be 3.2 m / s, the coiling speed of the coil box when coiling the steel plate is controlled to be 4 m / s, the offset of the inlet side guide plate of the coil box is adjusted, the opening degree of the first stabilizer and the second stabilizer of the coil box is determined according to the production state of the steel plate in the coil box, the opening degree of the flying shear side guide plate is adjusted, the head of the steel plate is controlled to pass through the phosphorus removal device and the dust suppression water device of the finishing rolling mill train, the rolling load of the first rolling mill to the sixth rolling mill of the finishing rolling mill train is adjusted, the angles of the third loop, the fourth loop and the fifth loop of the finishing rolling mill train are controlled to be preset angles, the roll shifting value of each rolling mill of the finishing rolling mill train is set, when the head of the steel plate reaches the edger of the first rolling mill of the finishing rolling mill train, the pressure of the edger is controlled to be 5 tons, and the offset of the edger is controlled to be -15 mm, and the opening degree of the side guide plate of the finishing rolling mill train is adjusted. The heating temperature and the discharge temperature of the steel plate in the heating furnace are determined according to the width of the steel plate, and the heating time of the steel plate in the heating furnace is determined according to the entry temperature of the steel plate. If the width of the steel plate is less than 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1250℃-1260℃, the soaking section temperature of the heating furnace is controlled to be 1255℃, and the discharge temperature of the steel plate is controlled to be 1250℃-1260℃; If the width of the steel plate is greater than or equal to 1300 mm, the first heating section temperature of the heating furnace is controlled to be 1050℃, the second heating section temperature of the heating furnace is controlled to be 1260℃-1270℃, the soaking section temperature of the heating furnace is controlled to be 1265℃, and the discharge temperature of the steel plate is controlled to be 1260℃-1270℃.

2. The method of claim 1, wherein, The heating time of the steel plate in the heating furnace is determined according to the entry temperature of the steel plate. If the entry temperature of the steel plate is less than 300℃, the heating time of the steel plate in the heating furnace is controlled to be 180 min; If the entry temperature of the steel plate is greater than or equal to 300℃ and less than or equal to 500℃, the heating time of the steel plate in the heating furnace is controlled to be 170 min; If the furnace entry temperature of the steel plate is greater than 500℃, the heating time of the steel plate in the heating furnace is controlled to be 160 min.

3. The method of claim 1, wherein, The preset offset is 50 mm.

4. The method of claim 1, wherein, The adjustment of the offset of the entry side guide plate of the plate coiling box includes: When the head of the steel plate reaches the entry side guide plate of the plate coiling box, the offset of the entry side guide plate is controlled to be 50 mm; when the middle part of the steel plate reaches the entry side guide plate of the plate coiling box, the offset of the entry side guide plate is controlled to be 20 mm; and when the tail of the steel plate reaches the entry side guide plate of the plate coiling box, the offset of the entry side guide plate is controlled to be 20 mm. When the head of the steel plate reaches the plate coiling box, the opening degree of the first stabilizer of the plate coiling box is controlled to be 120 mm. When the steel plate is coiled in the plate coiling box, the opening degree of the first stabilizer of the plate coiling box is controlled to be 120 mm. When the steel plate is coiled in the plate coiling box, the opening degree of the first stabilizer of the plate coiling box is controlled to be -20 mm. When the steel plate is uncoiled in the plate coiling box, the opening degree of the first stabilizer of the plate coiling box is controlled to be 80 mm. When the head of the steel plate reaches the second stabilizer of the plate coiling box, the opening degree of the second stabilizer is controlled to be 120 mm. When the middle part of the steel plate reaches the second stabilizer of the plate coiling box, the opening degree of the second stabilizer is controlled to be 40 mm.

5. The method of claim 1, wherein, The adjustment of the opening degree of the flying shear side guide plate includes: When the head of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 30 mm. When the middle part of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be -10 mm. When the tail of the steel plate reaches the flying shear side guide plate, the opening degree of the flying shear side guide plate is controlled to be 0 mm.

6. The method of claim 1, wherein, The adjustment of the rolling mill load of the first rolling mill to the sixth rolling mill of the finishing rolling mill train includes: The rolling mill load of the first rolling mill of the finishing rolling mill train is controlled to be 50 kw, and the rolling mill load of the second rolling mill, the third rolling mill, the fourth rolling mill, the fifth rolling mill and the sixth rolling mill is controlled to be 42 kw-20 kw.

7. The method of claim 1, wherein, The preset angle is 16°-18°.

8. The method of claim 1, wherein, The setting of the roll shifting value of each rolling mill of the finishing rolling mill train includes: The roll shifting value of the first rolling mill of the finishing rolling mill train is controlled to be -10 mm-50 mm; The roll shifting value of the second rolling mill of the finishing rolling mill train is controlled to be 10 mm-40 mm; The roll shifting value of the third rolling mill of the finishing rolling mill train is controlled to be 0 mm-40 mm; The roll shifting value of the fourth rolling mill of the finishing rolling mill train is controlled to be 20 mm-60 mm; The roll shifting value of the fifth rolling mill of the finishing rolling mill train is controlled to be 10 mm-50 mm; The roll shifting value of the sixth rolling mill of the finishing rolling mill train is determined according to the plate shape rolling data of the steel plate of the first rolling mill to the fifth rolling mill of the finishing rolling mill train.

9. The method of claim 1, wherein, The adjustment of the side guide plate opening degree of the finishing rolling mill train includes: When the steel plate reaches the first finishing side guide plate of the finishing rolling unit, the opening degree of the first finishing side guide plate is controlled to be 20; when the steel plate reaches the second finishing side guide plate of the finishing rolling unit, the opening degree of the second finishing side guide plate is controlled to be 20; when the steel plate reaches the third finishing side guide plate of the finishing rolling unit, the opening degree of the third finishing side guide plate is controlled to be 30; When the head and middle part of the steel plate reach the fourth finishing side guide plate of the finishing rolling unit, the opening degree of the fourth finishing side guide plate is controlled to be 30, and when the tail of the steel plate reaches the fourth finishing side guide plate of the finishing rolling unit, the opening degree of the fourth finishing side guide plate is controlled to be 40; When the head and middle part of the steel plate reach the fifth finishing side guide plate of the finishing rolling unit, the opening degree of the fifth finishing side guide plate is controlled to be 30, and when the tail of the steel plate reaches the fifth finishing side guide plate of the finishing rolling unit, the opening degree of the fifth finishing side guide plate is controlled to be 60.

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