Method for improving uniformity of coating on ultrahigh-strength steel

Abstract

This application relates to the field of steel rolling technology and discloses a method for improving the uniformity of coating on ultra-high strength steel. The method includes: obtaining the set annealing temperature of the ultra-high strength steel to be annealed, and annealing the ultra-high strength steel based on the set annealing temperature and a heating temperature range of 10–15°C; obtaining the set tension of the ultra-high strength steel in the soaking zone of the annealing furnace, and controlling the tension of the ultra-high strength steel in the soaking zone of the annealing furnace to increase to a target tension, the target tension being obtained by adding the set tension and the increased tension, the increased tension being 10% of the set tension; and hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, wherein the diameter of the stabilizing roller body used in the hot-dip galvanizing process is 280 mm, the diameter of the submerged roller bushing and the bearing diameter are 130 mm, the height of the air knife and the zinc liquid surface in the zinc pot is 450–550 mm, and the distance between the edge baffle and the ultra-high strength steel is 0.1–2.4 mm. The technical solution proposed in this application can improve the uniformity of the coating on ultra-high strength steel.

Description

Technical Field

[0001] This application relates to the field of steel rolling technology and discloses a method for improving the uniformity of coatings on ultra-high strength steel. Background Technology

[0002] With the increasing demands for automotive body safety performance, ultra-high-strength steel is being used more and more extensively in automotive bodies. During the production process, ultra-high-strength steel with a width exceeding 1.2 meters is prone to poor coating uniformity, thus affecting the overall coating quality. This is mainly due to residual stress within the high-strength steel and plastic deformation at the zinc pot location, resulting in poor strip shape at the air knife location and varying distances between the upper and lower surfaces of the strip and the air knife. Therefore, this application proposes a method to improve the coating uniformity of ultra-high-strength steel, which can improve the coating uniformity to a certain extent. Summary of the Invention

[0003] This application relates to the field of steel rolling technology and discloses a method for improving the uniformity of coatings on ultra-high strength steel. It can improve the uniformity of coatings on ultra-high strength steel to a certain extent.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to a first aspect of the embodiments of this application, a method for improving the uniformity of coatings on ultra-high strength steel is provided. The method includes: obtaining an annealing set temperature for the ultra-high strength steel to be annealed, and annealing the ultra-high strength steel to be annealed based on a target annealing temperature range, wherein the target annealing temperature range is obtained by adding the annealing set temperature and a heating temperature range, wherein the heating temperature range is 10–15°C; obtaining a set tension of the ultra-high strength steel in the soaking zone of the annealing furnace, and controlling the ultra-high strength steel in the soaking zone of the annealing furnace. The tension in the hot section is increased to the target tension, which is obtained by adding the set tension and the increased tension, wherein the increased tension is 10% of the set tension; the annealed ultra-high strength steel is hot-dip galvanized in a zinc pot, wherein the diameter of the stabilizing roller body used in the hot-dip galvanizing process is 280 mm, the diameter of the submerged roller bushing and the bearing diameter are 130 mm, the height of the air knife and the zinc liquid surface in the zinc pot is 450-550 mm, and the distance between the ultra-high strength steel edge baffle and the ultra-high strength steel is 0.1-2.4 mm.

[0006] In one embodiment of this application, based on the foregoing scheme, the method further includes: controlling a scraper to remove zinc dross adhering to the submerged roller surface, the stabilizing roller surface, and the correcting roller surface at a set time.

[0007] In one embodiment of this application, based on the foregoing scheme, the method further includes: controlling the distance between the air knife and the ultra-high strength steel to be 8mm.

[0008] In one embodiment of this application, based on the aforementioned scheme, the hot-dip galvanizing treatment of the annealed ultra-high strength steel using a zinc pot includes: controlling the annealed ultra-high strength steel to enter the zinc pot, and hot-dip galvanizing the annealed ultra-high strength steel using liquid zinc in the zinc pot, so as to form a zinc coating on the surface of the ultra-high strength steel, thereby obtaining galvanized ultra-high strength steel.

[0009] In one embodiment of this application, based on the aforementioned scheme, after hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, the method further includes: passivating the galvanized ultra-high strength steel with a sodium dichromate solution to form a passivation film on the surface of the galvanized ultra-high strength steel, the passivation film being used to improve the corrosion resistance of the galvanized ultra-high strength steel.

[0010] In one embodiment of this application, based on the foregoing scheme, after passivating the galvanized ultra-high strength steel with sodium dichromate solution, the method further includes: rinsing the galvanized ultra-high strength steel in a rinsing device to wash away the passivation solution remaining on the galvanized ultra-high strength steel.

[0011] In one embodiment of this application, based on the foregoing scheme, after the galvanized ultra-high strength steel is brought into the rinsing equipment for rinsing, the method further includes: bringing the galvanized ultra-high strength steel into a leveling machine for leveling treatment, so as to improve the plate shape of the galvanized ultra-high strength steel and eliminate the yield plateau.

[0012] In one embodiment of this application, based on the aforementioned scheme, before hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, the method further includes: pickling the ultra-high strength steel with a sulfuric acid solution to activate the surface of the ultra-high strength steel and improve the adhesion of the ultra-high strength steel surface.

[0013] In one embodiment of this application, based on the foregoing scheme, before pickling the ultra-high strength steel with sulfuric acid solution, the method further includes: performing alkaline washing treatment on the surface of the ultra-high strength steel with sodium hydroxide solution to remove oil stains from the surface of the ultra-high strength steel.

[0014] According to a second aspect of the embodiments of this application, an ultra-high strength steel is provided, which is prepared by the method described in any of the above embodiments.

[0015] In the technical solution proposed in this application, the annealing set temperature of the ultra-high strength steel to be annealed is obtained, and the ultra-high strength steel to be annealed is annealed based on the target annealing temperature range. The target annealing temperature range is obtained by adding the annealing set temperature and the heating temperature range, and the heating temperature range is 10-15℃. The tension of the ultra-high strength steel in the soaking section of the annealing furnace is obtained, and the tension of the ultra-high strength steel in the soaking section of the annealing furnace is controlled to be increased to the target tension. The target tension is obtained by adding the set tension and the increased tension, and the increased tension is 10% of the set tension. The annealed ultra-high strength steel is then hot-dip galvanized in a zinc pot. The diameter of the stabilizing roller body used in the hot-dip galvanizing process is 280mm, the diameter of the submerged roller bushing and the diameter of the bearing are 130mm, the height of the surface of the zinc liquid in the air knife and the zinc pot is 450-550mm, and the distance between the edge baffle and the ultra-high strength steel is 0.1-2.4mm. The technical solution proposed in this application can improve the uniformity of ultra-high strength steel coating to a certain extent.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0018] Figure 1 A flowchart of a method for improving the uniformity of ultra-high strength steel coatings according to an embodiment of this application is shown;

[0019] Figure 2 A line graph illustrating the transverse uniformity of the ultra-high strength steel coating in the comparative embodiments of this application is shown.

[0020] Figure 3 A line graph illustrating the transverse uniformity of the ultra-high strength steel coating in the first embodiment of this application is shown. Detailed Implementation

[0021] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0022] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0023] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0024] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0025] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0027] The implementation details of the technical solutions in the embodiments of this application are described in detail below:

[0028] Figure 1 A flowchart of a method for improving the uniformity of ultra-high strength steel coatings according to an embodiment of this application is shown.

[0029] like Figure 1 As shown, the method for improving the uniformity of ultra-high strength steel coating includes at least steps 110 to 150.

[0030] The following will be about Figure 1Steps 110 to 150 are described in detail below:

[0031] In step 110, the annealing set temperature of the ultra-high strength steel to be annealed is obtained, and the ultra-high strength steel to be annealed is annealed based on the target annealing temperature range. The target annealing temperature range is obtained by adding the annealing set temperature and the heating temperature range, and the heating temperature range is 10 to 15°C.

[0032] In this application, the annealing set temperature of the ultra-high strength steel to be annealed is obtained, and the annealing temperature of the ultra-high strength steel to be annealed is appropriately increased based on the heating temperature range to obtain the actual annealing temperature. The ultra-high strength steel to be annealed is then annealed based on the actual annealing temperature to release the residual stress inside the ultra-high strength steel.

[0033] Continue to refer to Figure 1 In step 130, the set tension of the ultra-high strength steel in the soaking section of the annealing furnace is obtained, and the tension of the ultra-high strength steel in the soaking section of the annealing furnace is controlled to be increased to the target tension. The target tension is obtained by adding the set tension and the increased tension, and the increased tension is 10% of the set tension.

[0034] In this application, the set tension of the ultra-high strength steel in the soaking zone of the annealing furnace is obtained, and the required increase in lifting tension is determined based on the set tension. The actual tension of the ultra-high strength steel in the soaking zone of the annealing furnace is determined based on the set tension and the lifting tension, so as to increase the plastic deformation of the ultra-high strength steel in the high-temperature zone and improve the plate shape of the ultra-high strength steel entering the zinc pot.

[0035] Continue to refer to Figure 1 In step 150, the annealed ultra-high strength steel is hot-dip galvanized in a zinc pot. The diameter of the stabilizing roller body used in the hot-dip galvanizing process is 280 mm, the diameter of the submerged roller bushing and the diameter of the bearing are 130 mm, the height of the air knife and the zinc liquid surface in the zinc pot is 450-550 mm, and the distance between the ultra-high strength steel edge baffle and the ultra-high strength steel is 0.1-2.4 mm.

[0036] In this application, annealed ultra-high strength steel is hot-dip galvanized in a zinc pot to coat it with a zinc coating. The diameter of the stabilizing roller used in the hot-dip galvanizing process is increased from 250mm to 280mm to improve the stiffness of the correcting roller and the wear resistance of its bushing. The diameter of the submerged roller bushing and the bearing diameter are increased from 120mm to 130mm to improve the correcting roller's ability to eliminate C-warping after the ultra-high strength steel leaves the pot.

[0037] In this application, the height of the surface of the liquid zinc in the air knife and zinc pot is set to 450-550mm to reduce the influence of C-curve on the lateral thickness of the coating. The distance between the edge baffle of the ultra-high strength steel and the ultra-high strength steel is set to be less than 0.3 times the distance between the air knife and the ultra-high strength steel. If the distance between the air knife and the ultra-high strength steel is 8mm, then the distance between the edge baffle of the ultra-high strength steel and the ultra-high strength steel is set to be less than 2.4mm to prevent the coating thickness at the edge of the ultra-high strength steel from increasing.

[0038] In one embodiment of this application, the method further includes: controlling a scraper to remove zinc dross adhering to the submerged roller surface, the stabilizing roller surface, and the correcting roller surface at a set time.

[0039] In this application, the scraper is controlled to remove zinc dross adhering to the surface of the sinking roller, the surface of the stabilizing roller, and the surface of the correcting roller according to a set time, so as to prevent the situation where there is too much zinc dross on the surface of the sinking roller, the surface of the stabilizing roller, and the surface of the correcting roller without cleaning, so as to avoid the poor plate shape of the ultra-high strength steel due to slag formation.

[0040] In one embodiment of this application, the method further includes controlling the distance between the air knife and the ultra-high strength steel to be 8 mm.

[0041] In one embodiment of this application, the hot-dip galvanizing treatment of annealed ultra-high strength steel in a zinc pot includes: controlling the annealed ultra-high strength steel to enter the zinc pot, and hot-dip galvanizing the annealed ultra-high strength steel with liquid zinc in the zinc pot, so as to form a zinc coating on the surface of the ultra-high strength steel, thereby obtaining galvanized ultra-high strength steel.

[0042] In this application, the annealed ultra-high strength steel is controlled to enter a zinc pot, and the annealed ultra-high strength steel is hot-dip galvanized by the liquid zinc in the zinc pot. The temperature of the zinc liquid in the zinc pot can be controlled at 450-455℃, or the zinc liquid can be heated to a set temperature according to actual needs.

[0043] In this application, the ultra-high strength steel can be soaked in a flux before hot-dip galvanizing to activate the surface of the ultra-high strength steel and improve the quality of zinc plating. The soaked ultra-high strength steel can be dried to prevent the zinc from exploding too early or being missed during zinc plating if it is put into the zinc pot too late.

[0044] In one embodiment of this application, after hot-dip galvanizing the annealed ultra-high-strength steel in a zinc pot, the method further includes: passivating the galvanized ultra-high-strength steel with a sodium dichromate solution to form a passivation film on the surface of the galvanized ultra-high-strength steel, the passivation film being used to improve the corrosion resistance of the galvanized ultra-high-strength steel.

[0045] In this application, the galvanized ultra-high strength steel can be passivated by electrolytic passivation. The passivation solution can be sodium dichromate solution. The passivation treatment forms a passivation film on the surface of the galvanized ultra-high strength steel. The passivation film can prevent the galvanized ultra-high strength steel from corrosion during transportation and storage, and can improve its durability against sulfite corrosion.

[0046] In one embodiment of this application, after passivating the galvanized ultra-high strength steel with sodium dichromate solution, the method further includes: rinsing the galvanized ultra-high strength steel in a rinsing device to wash away any passivation solution remaining on the galvanized ultra-high strength steel.

[0047] In this application, the galvanized ultra-high strength steel is brought into a rinsing device for rinsing to wash away the passivation solution remaining on the galvanized ultra-high strength steel and to a certain extent reduce the number of spot defects appearing on the galvanized ultra-high strength steel.

[0048] In one embodiment of this application, after the galvanized ultra-high strength steel is rinsed in a rinsing device, the method further includes: rinsing the galvanized ultra-high strength steel in a leveling machine to improve the shape of the galvanized ultra-high strength steel and eliminate the yield plateau.

[0049] In this application, the galvanized ultra-high strength steel is brought into a leveling machine for leveling treatment, which can improve the shape of the galvanized ultra-high strength steel, improve the surface smoothness of the galvanized ultra-high strength steel, eliminate yield plateaus, and reduce various shape defects to a certain extent through one or more leveling processes.

[0050] In one embodiment of this application, before hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, the method further includes: pickling the ultra-high strength steel with a sulfuric acid solution to activate the surface of the ultra-high strength steel and improve the adhesion of the ultra-high strength steel surface.

[0051] In this application, sulfuric acid solution can be used to pickle the ultra-high strength steel, or other acidic solutions can be used to pickle the ultra-high strength steel. Sulfuric acid solution is used to remove oxides on the surface of the ultra-high strength steel and improve the adhesion of the ultra-high strength steel surface, thereby improving the adhesion of zinc on the surface of the ultra-high strength steel during hot-dip galvanizing.

[0052] In one embodiment of this application, before pickling the ultra-high strength steel with sulfuric acid solution, the method further includes: performing alkaline washing on the surface of the ultra-high strength steel with sodium hydroxide solution to remove oil stains from the surface of the ultra-high strength steel.

[0053] In this application, sodium hydroxide solution can be used to treat the ultra-high strength steel, or other alkaline solutions can be used to pickle the ultra-high strength steel. Sodium hydroxide solution is used to remove oil stains from the surface of the ultra-high strength steel, which can prevent the ultra-high strength steel from being missed during hot-dip galvanizing.

[0054] To make this solution more easily understandable to those skilled in the art, the following will be combined with... Figure 2 and Figure 3 This document will explain the technical parameters involved in the production process of ultra-high strength steel as proposed in this plan.

[0055] Figure 2 A line graph illustrating the transverse uniformity of the ultra-high strength steel coating in the comparative embodiments of this application is shown.

[0056] Comparative Example:

[0057] Specifically, in the embodiments of this application, the ultra-high strength steel involved has a thickness of 3.0 mm, a width of 1300 mm, and a strength level of 980 MPa.

[0058] During the production of ultra-high strength steel, the annealing temperature in the annealing furnace is 830℃, and the unit tension of the ultra-high strength steel in the soaking zone of the annealing furnace is 20MPa.

[0059] After annealing, the ultra-high strength steel is hot-dip galvanized in a zinc pot. The diameter of the stabilizing roller inside the zinc pot is 250mm, and the diameter of the submerged roller bushing and bearing is 120mm. The feed amount of the correcting roller is dynamically adjusted according to the position and shape of the plate in the air knife.

[0060] Furthermore, during the production of ultra-high strength steel, the continuous use of the scrapers on the submerged roll, the correcting roll, and the stabilizing roll is ensured to remove zinc dross adhering to the surface of the submerged roll, the surface of the stabilizing roll, and the surface of the correcting roll.

[0061] In the production process of ultra-high strength steel, the distance between the air knife and the ultra-high strength steel is set to 9mm, the height of the air knife from the zinc liquid surface is 440mm, and the distance between the air knife edge baffle and the strip steel is controlled to 3mm.

[0062] Based on the aforementioned devices, ultra-high strength steel is hot-dip galvanized to obtain galvanized ultra-high strength steel. The uniformity of the coating on the upper and lower surfaces of the galvanized ultra-high strength steel is as follows: Figure 2 As shown, it can be seen that the coating uniformity of the upper and lower surfaces of the galvanized ultra-high strength steel is poor.

[0063] Figure 3 A line graph illustrating the transverse uniformity of the ultra-high strength steel coating in the first embodiment of this application is shown.

[0064] First embodiment:

[0065] Specifically, in the embodiments of this application, the ultra-high strength steel involved has a thickness of 3.0 mm, a width of 1300 mm, and a strength level of 980 MPa.

[0066] During the production of ultra-high strength steel, the annealing temperature in the annealing furnace is 840℃, and the unit tension of the ultra-high strength steel in the soaking zone of the annealing furnace is 22MPa.

[0067] After annealing, the ultra-high strength steel is hot-dip galvanized in a zinc pot. The diameter of the stabilizing roller inside the zinc pot is 280mm, and the diameter of the submerged roller bushing and bearing is 130mm. The feed amount of the correcting roller is dynamically adjusted according to the position and shape of the plate in the air knife.

[0068] Furthermore, during the production of ultra-high strength steel, the continuous use of the scrapers on the submerged roll, the correcting roll, and the stabilizing roll is ensured to remove zinc dross adhering to the surface of the submerged roll, the surface of the stabilizing roll, and the surface of the correcting roll.

[0069] In the production process of ultra-high strength steel, the distance between the air knife and the ultra-high strength steel is set to 8mm, the height of the air knife from the zinc liquid surface is 460mm, and the distance between the air knife edge baffle and the strip steel is controlled to 2mm.

[0070] Based on the aforementioned devices, ultra-high strength steel is hot-dip galvanized to obtain galvanized ultra-high strength steel. The uniformity of the coating on the upper and lower surfaces of the galvanized ultra-high strength steel is as follows: Figure 3 As shown, it can be seen that the uniformity of the coating on the upper and lower surfaces of the galvanized ultra-high strength steel is improved to a certain extent.

[0071] The one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0072] This application proposes a method to improve the uniformity of coatings on ultra-high strength steel, which can improve the uniformity of coatings on ultra-high strength steel to a certain extent.

[0073] This application proposes a method to improve the uniformity of coating on ultra-high strength steel, which provides good guidance for the production of wide-specification ultra-high strength steel with requirements for corrosion resistance and welding quality.

[0074] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0075] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0076] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for improving the uniformity of coatings on ultra-high strength steel, characterized in that, The method includes: The annealing set temperature of the ultra-high strength steel to be annealed is obtained, and the ultra-high strength steel to be annealed is annealed based on the target annealing temperature range. The target annealing temperature range is obtained by adding the annealing set temperature and the heating temperature range, and the heating temperature range is 10~15℃. The set tension of the ultra-high strength steel in the soaking section of the annealing furnace is obtained, and the tension of the ultra-high strength steel in the soaking section of the annealing furnace is controlled to be increased to the target tension. The target tension is obtained by adding the set tension and the increased tension, and the increased tension is 10% of the set tension. The annealing temperature of the ultra-high strength steel in the annealing furnace is 840℃, and the unit tension of the ultra-high strength steel in the soaking section of the annealing furnace is 22MPa. The annealed ultra-high strength steel is hot-dip galvanized in a zinc pot. The diameter of the stabilizing roller body used in the hot-dip galvanizing process is 280mm, the diameter of the submerged roller bushing and the diameter of the bearing are 130mm, the height of the air knife and the zinc liquid surface in the zinc pot is 450~550mm, and the distance between the ultra-high strength steel edge baffle and the ultra-high strength steel is 0.1~2.4mm. The hot-dip galvanizing treatment of annealed ultra-high strength steel using a zinc pot includes: The annealed ultra-high strength steel is controlled to enter a zinc pot, and the annealed ultra-high strength steel is hot-dip galvanized by the liquid zinc in the zinc pot, so that a zinc coating is formed on the surface of the ultra-high strength steel, and galvanized ultra-high strength steel is obtained. After hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, the method further includes: The galvanized ultra-high strength steel is passivated by sodium dichromate solution to form a passivation film on the surface of the galvanized ultra-high strength steel, and the passivation film is used to improve the corrosion resistance of the galvanized ultra-high strength steel. After passivating the galvanized ultra-high strength steel with sodium dichromate solution, the method further includes: The galvanized ultra-high strength steel is brought into a rinsing device for rinsing to wash away the passivation solution remaining on the galvanized ultra-high strength steel. The galvanized ultra-high strength steel is then brought into a leveling machine for leveling treatment to improve the plate shape of the galvanized ultra-high strength steel and eliminate the yield plateau.

2. The method according to claim 1, characterized in that, The method further includes: The scraper is controlled to remove zinc dross adhering to the surface of the submerged roller, the surface of the stabilizing roller, and the surface of the correcting roller according to a set time.

3. The method according to claim 1, characterized in that, The method further includes: The distance between the air knife and the ultra-high strength steel is controlled to be 8mm.

4. The method according to claim 1, characterized in that, Before hot-dip galvanizing the annealed ultra-high strength steel in a zinc pot, the method further includes: The ultra-high strength steel is pickled with sulfuric acid solution to activate its surface and improve its adhesion.

5. The method according to claim 4, characterized in that, Before pickling the ultra-high strength steel with sulfuric acid solution, the method further includes: The surface of the ultra-high strength steel is treated with an alkaline solution of sodium hydroxide to remove oil stains.

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