CN117448544A

CN117448544A - Low-carbon nickel pre-plated steel strip and preparation method thereof

Info

Publication number: CN117448544A
Application number: CN202311272767.5A
Authority: CN
Inventors: 周建; 刘再旺; 张良; 朱防修; 李飞; 缪成亮; 杨利斌; 乔建军; 刘顺明; 周欢; 莫志英; 刘武华; 郑艳坤; 马壮
Original assignee: Shougang Jingtang United Iron and Steel Co Ltd
Current assignee: Shougang Jingtang United Iron and Steel Co Ltd
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2024-01-26

Abstract

The invention provides a low-carbon nickel pre-plating steel belt and a preparation method thereof, belonging to the technical field of steel production. The preparation method of the nickel pre-plated steel strip comprises the following steps: heating, rolling in stages, cooling after rolling and coiling the slab with the set chemical composition to obtain a hot rolled coil; pickling and cold continuous rolling are carried out on the hot rolled coil, and a chilled coil is obtained; nickel plating is carried out on the chilled coil, and the thickness of the nickel layer of the nickel plating is controlled to obtain a nickel-plated coil; and continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain the nickel-plated steel strip. The nickel-plated steel strip prepared by the method can meet the severe test conditions and service environment of the power battery, and solves the problem that the existing nickel-plated steel strip for the battery case is poor in corrosion resistance.

Description

Low-carbon nickel pre-plated steel strip and preparation method thereof

Technical Field

The application relates to the technical field of steel production, in particular to a low-carbon nickel pre-plating steel belt and a preparation method thereof.

Background

Along with the cooling of new energy automobile subsidy, competition among lithium battery enterprises is gradually upgraded, production cost and product quality become competitive sharp weapons, and enterprises do not pursue the energy density of batteries any more, so that the safety and consistency of the batteries are more emphasized. The battery shell not only plays a role in bearing the battery structure, but also plays a key role in the safety performance and the storage electrical performance of the battery, and is a key part in ensuring the quality of the battery. When the nickel-plated steel is applied to the battery shell, the chemical property is stable, and the stability of the internal environment of the battery can be ensured. And nickel is electroplated on the steel strip, so that the nickel-plated steel strip can be produced in batches, has low cost and is suitable for industrial production. Therefore, nickel-plated steel cases are increasingly being appreciated by some battery enterprises in China.

In order to ensure that the battery can still keep better performance in an acidic or alkaline environment, is not corroded by acidic or alkaline substances, meets the requirement of the battery on safety performance, and how to further improve the corrosion resistance of the nickel pre-plated steel strip for the battery shell becomes a problem to be solved.

Disclosure of Invention

The application provides a low-carbon nickel pre-plating steel belt and a preparation method thereof, which are used for solving the technical problem that the corrosion resistance of the existing nickel pre-plating steel belt is poor.

In a first aspect, the present application provides a method for preparing a low-carbon nickel-plated steel strip, the method comprising:

heating, rolling in stages, cooling after rolling and coiling the slab with the set chemical composition to obtain a hot rolled coil;

pickling and cold continuous rolling are carried out on the hot rolled coil, and a chilled coil is obtained;

nickel plating is carried out on the chilled coil, and the thickness of the nickel layer of the nickel plating is controlled to obtain a nickel-plated coil;

continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section and process parameters of the soaking section are controlled.

Optionally, the process parameters of the soaking section include: soaking temperature and soaking time; wherein,

the soaking temperature is 580-680 ℃, and the soaking time and the soaking temperature meet the following relational expression: t= -0.979 x t+ (710-730), T being the soaking time in s, T being the soaking temperature in c.

Optionally, continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section, and controlling the technological parameters of the soaking section, comprising:

continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; the continuous annealing comprises a soaking section, a slow cooling section, a fast cooling section and an overaging section, and the process parameters of the soaking section and the temperatures of the slow cooling section, the fast cooling section and the overaging section are controlled;

the temperature of the slow cooling section is 500-600 ℃, the temperature of the fast cooling section is 400-420 ℃, and the temperature of the overaging section is 360-400 ℃.

Optionally, the flat elongation is 1.0-1.5%.

Optionally, the nickel layer of the nickel plating has a thickness of 2 μm to 4 μm.

Optionally, the slab with the set chemical composition is heated, rolled in stages, cooled after rolling and coiled to obtain a hot rolled coil; wherein,

the heating temperature is 1050-1150 ℃, and the heating time is 120-180 min; and/or the number of the groups of groups,

the staged rolling comprises rough rolling and finish rolling, wherein the initial rolling temperature of the rough rolling is 1000-1050 ℃, and the final rolling temperature of the finish rolling is 870-950 ℃; and/or the number of the groups of groups,

the cooling after rolling adopts laminar cooling; and/or the number of the groups of groups,

the coiling temperature is 500-650 ℃.

Optionally, pickling and cold continuous rolling are carried out on the hot rolled coil to obtain a chilled coil; wherein,

the rolling reduction of the cold continuous rolling is 75-85%.

Optionally, the setting chemical composition includes:

C. si, mn, S, P, alt, B, nb, N, [ O ] and Fe; wherein, the mass fraction of the material is calculated,

the content of C is 0.02-0.08%, the content of Si is less than or equal to 0.03%, the content of Mn is 0.1-0.8%, the content of S is less than or equal to 0.008%, the content of P is less than or equal to 0.012%, the content of Alt is 0.03-0.07%, the content of B is 0.001-0.003%, the content of Nb is 0.004-0.008%, the content of N is less than or equal to 0.003%, and the content of [ O ] is less than or equal to 0.003%.

In a second aspect, the present application provides a low-carbon nickel-plated steel strip, the nickel-plated steel strip being prepared by the method according to any one of the embodiments of the first aspect;

the yield strength of the nickel-plated steel strip is 260-300 MPa, the tensile strength is 360-420 MPa, the elongation A50 is more than or equal to 38%, and the anisotropy Deltar value is less than or equal to 0.25.

Optionally, the thickness of the alloying Ni-Fe layer formed by diffusion of the nickel layer and the steel matrix is 1.4-1.6 μm.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

the cooperative control of mechanical properties and the Ni-Fe alloying layer is realized through the alloying annealing process of the nickel-plated steel strip, the nickel layer on the surface of the steel substrate is subjected to annealing treatment, the hardness is reduced, the nickel layer is not easy to fall off in the subsequent stamping process, and an alloying Fe-Ni bonding layer can be formed. The Fe-Ni alloy layer has quite high compactness, the Fe-Ni alloy layer, the Fe matrix on the surface of the Fe-Ni alloy layer and the nickel plating layer have quite high binding force, and the corrosion resistance mechanism of the multi-layer nickel with different components formed by the Fe-Ni alloy layer and the electroplated nickel layer enables the corrosion resistance performance of the steel shell surface to be remarkably improved.

The surface appearance of the nickel-plated steel strip is smoother, the crystal grains are uniform, and the corrosion resistance is better through a leveling process.

The nickel plating layer thickness in the nickel plating process of the steel strip is controlled, so that the nickel plating layer with uniform plating layer thickness and accurate plating layer thickness can be obtained, and the obtained nickel plating steel strip has good corrosion resistance.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the description of the embodiments or the prior art will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic flow chart of a method for preparing a low-carbon nickel pre-plated steel strip according to an embodiment of the present application;

fig. 2 is a photograph of a metallographic structure provided in example 1 of the present application;

fig. 3 is a photograph of a 72-hour neutral salt spray experiment of the nickel-plated steel strip provided in example 1 of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

Various embodiments of the present application may exist in a range format; it should be understood that the description in a range format is merely for convenience and brevity and should not be interpreted as a rigid limitation on the scope of the application. It is therefore to be understood that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that a description of a range from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, wherever applicable. In addition, whenever a numerical range is referred to herein, it is meant to include any reference number (fractional or integer) within the indicated range.

In the description of the present specification, the terms "include," "comprise," and the like are intended to mean "include, but are not limited to. Relational terms such as "first" and "second", and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Herein, "and/or" describing an association relationship of an association object means that there may be three relationships, for example, a and/or B, may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural. Herein, "at least one" means one or more, and "a plurality" means two or more. "at least one", "at least one" or the like refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

Unless specifically indicated otherwise, the various raw materials, reagents, instruments, equipment, and the like used in this application are commercially available or may be prepared by existing methods.

In a first aspect, the present application provides a method for preparing a low-carbon nickel-plated steel strip, referring to fig. 1, the method includes:

s1, heating, rolling in stages, cooling after rolling and coiling a slab with a set chemical composition to obtain a hot rolled coil;

in the embodiment of the application, before the step S1, the method further includes pretreatment of molten iron, converter smelting and refining; and (5) continuously casting to obtain a plate blank.

In some embodiments, the setting the chemical composition may include: C. si, mn, S, P, alt, B, nb, N, [ O ] and Fe; wherein, the mass fraction of the material is calculated,

the content of C may be 0.02 to 0.08%, the content of Si may be 0.03% or less, the content of Mn may be 0.1 to 0.8%, the content of S may be 0.008% or less, the content of P may be 0.012% or less, the content of Alt may be 0.03 to 0.07%, the content of B may be 0.001 to 0.003%, the content of Nb may be 0.004 to 0.008%, the content of N may be 0.003% or less, and the content of [ O ] may be 0.003% or less.

In the embodiment of the application, the positive effect of controlling the content of C to be 0.02-0.08 percent is as follows: in low carbon steel, the carbon content is a guarantee of strength, and is beneficial to impact resistance and pressure resistance of steel products. However, when the C content is too high, the plasticity of the steel becomes poor, and the formability is impaired. Specifically, the content of C may be 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, etc.

The positive effect of controlling the content of Si to be less than or equal to 0.03 percent is that: si is used as a deoxidizer for removing oxygen from molten steel, and in low carbon steel, a high Si content increases the strength of steel but affects the plasticity of steel, so that Si element is controlled to a low level. Specifically, the content of Si may be 0.01%, 0.02%, 0.03%, or the like.

The positive effect of controlling the Mn content to be 0.1-0.8 percent: mn reacts with S to generate MnS, so that S brittleness is eliminated, and meanwhile, mn can improve the strength of steel, reduce plasticity and is not beneficial to deep drawing. Specifically, the Mn content may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, etc.

The positive effect of controlling the S content to be less than or equal to 0.008 percent is that: generally, S is an impurity element in steel, and is liable to form brittle substances. When the sulfur content is too high, sulfide inclusions are easily formed, and breakage is caused when the battery case is press-molded, so that the lower the content, the better. Specifically, the content of S may be 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, etc.

The positive effect of controlling the content of P to be less than or equal to 0.012 percent is that: p is an impurity element, is easy to gather at a grain boundary, can increase brittleness of the steel plate, is a remarkable solid solution strengthening element, improves strength of the steel plate, and affects plasticity of the steel. Specifically, the content of P may be 0.002%, 0.004%, 0.006%, 0.008%, 0.010%, 0.012%, or the like.

The positive effect of controlling the content of Alt to be 0.03-0.07 percent: alt is added as a deoxidizer in conventional processes. Alt reacts with N to form AlN, but AlN formation can reduce the content of solid solution N in steel and reduce the occurrence of overaging. Specifically, the content of Alt may be 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, or the like.

The positive effect of controlling the content of B to be 0.001-0.003 percent: b and N combine to form BN particles, so that the amount of solid solution N in steel can be reduced, and brittleness can be reduced. B is grain boundary segregation element, which is favorable for carbide precipitation in the crystal, is favorable for improving the performance uniformity, and reduces carbide precipitation difference caused by uneven temperature of the steel coil so as to keep the performance stable. Specifically, the content of B may be 0.001%, 0.002%, 0.003%, or the like.

The positive effect of controlling the Nb content to be 0.004-0.008 percent: the Nb element in a small amount mainly forms a solid solution, and the solid solution Nb can play a role of pinning grain boundaries and refining grains, and is advantageous in reducing anisotropy while improving strength and reducing plasticity as much as possible. However, when the Nb content is too high, nb combines with C element to form NbC particles, which excessively increases strength, and NbC causes a decrease in plasticity and a decrease in r value, which is disadvantageous for press forming. Specifically, the Nb content may be 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, etc.

The positive effect of controlling the content of N to be less than or equal to 0.003 percent is that: n exists in steel as a residual element and is an important element for over-aging, and the lower the content is, the better, but N element is controlled to be in a reasonable range due to restrictions in smelting level and cost. Specifically, the content of N may be 0.001%, 0.002%, 0.003%, or the like.

[ O ] represents total oxygen, and the positive effect of controlling the content of [ O ] to be less than or equal to 0.003 percent is that: the lower the oxygen content is, the higher the purity of the steel is, so that the defect of sand holes is not easy to occur in the stamping process of the battery steel shell, and the stamping forming is facilitated. Specifically, the content of [ O ] may be 0.001%, 0.002%, 0.003%, etc.

In some embodiments, the temperature of the heating may be 1050-1150 ℃ and the time of the heating may be 120-180 min.

In the embodiment of the application, the heating temperature is controlled to be 1050-1150 ℃, and the heating time is controlled to be 120-180 min, so that the method has the positive effects that: the steel billet can be ensured to be fully austenitized in the temperature range and the time range, and precipitation particles formed in the steel billet are only partially dissolved, so that the obtained particles are coarser, and higher r value is facilitated. Specifically, the heating temperature may be 1050 ℃, 1070 ℃, 1090 ℃, 1110 ℃, 1130 ℃, 1150 ℃ and the like, and the heating time may be 120min, 130min, 140min, 150min, 160min, 170min, 180min and the like.

In some embodiments, the staged rolling includes rough rolling, which may have an initial rolling temperature of 1000 ℃ to 1050 ℃, and finish rolling, which may have a final rolling temperature of 870 ℃ to 950 ℃.

In the embodiment of the application, the starting rolling temperature is controlled to be between 1000 ℃ and 1050 ℃, and the finishing rolling temperature is controlled to be 870 ℃ to 950 ℃ has the positive effects that: the whole rolling temperature interval is kept in an austenite region for rolling, and dynamic recrystallization can fully occur at the temperature for refining grains, so that the strength and the r value are improved. Specifically, the initial rolling temperature may be 1000 ℃, 1010 ℃, 1020 ℃, 1030 ℃, 1040 ℃, 1050 ℃, etc., and the final rolling temperature may be 870 ℃, 880 ℃, 890 ℃, 900 ℃, 910 ℃, 920 ℃, 930 ℃, 940 ℃, 950 ℃, etc.

In some embodiments, the post-rolling cooling may employ laminar cooling.

In some embodiments, the temperature of the coiling may be 500 ℃ to 650 ℃.

In the embodiment of the application, after laminar cooling and coiling are carried out after finishing rolling, the positive effects of controlling the coiling temperature to be 500-650 ℃ are that: transformation of austenite to ferrite + pearlite + cementite occurs before coiling, and as the coiling temperature increases, the ferrite grains become larger, while the pearlite ratio increases and the cementite ratio decreases. Wherein the ferrite grain size is inherited to the grain size after cold rolling annealing, which tends to make the grain size of the final product larger. Specifically, the winding temperature may be 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃, 600 ℃, 620 ℃, 640 ℃, 650 ℃, and the like.

S2, pickling and cold continuous rolling are carried out on the hot rolled coil, and a chilled coil is obtained;

in some embodiments, the cold continuous rolling reduction may be 75% to 85%.

In the embodiment of the application, the positive effect of controlling the rolling reduction of the cold continuous rolling to be 75% -85%: the adoption of higher cold rolling reduction can store enough distortion energy in the steel, is favorable for texture development, improves the forming performance of the steel plate, reduces the recrystallization temperature and is favorable for recrystallization after annealing. Specifically, the reduction ratio may be 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, or the like.

S3, carrying out nickel plating on the chilled coil, and controlling the thickness of the nickel layer of the nickel plating to obtain a nickel-plated coil;

in some embodiments, the nickel plating further comprises the steps of: degreasing, electrolytic degreasing, water washing, acid activation, cleaning, continuous nickel electroplating, cleaning and drying are carried out on the chilled rolls.

In some embodiments, the nickel layer of the nickel plating may have a thickness of 2 μm to 4 μm.

In the embodiment of the application, the positive effect of controlling the thickness of the nickel layer to be 2-4 μm is that: the nickel plating layer thickness in the nickel plating process of the steel strip is controlled, so that the nickel plating layer with uniform plating layer thickness and accurate plating layer thickness can be obtained, and the obtained nickel plating steel strip has good corrosion resistance. Specifically, the nickel layer thickness may be 2 μm, 3 μm, 4 μm, etc.

S4, continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section and process parameters of the soaking section are controlled.

In some embodiments, the process parameters of the soaking section include: soaking temperature and soaking time; wherein,

In some embodiments, the nickel-plated coil is continuously annealed and flattened, and the elongation of the flattening is controlled to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section, and controlling the technological parameters of the soaking section, comprising:

continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; the continuous annealing can comprise a soaking section, a slow cooling section, a fast cooling section and an overaging section, and the process parameters of the soaking section and the temperatures of the slow cooling section, the fast cooling section and the overaging section are controlled;

the temperature of the slow cooling section can be 500-600 ℃, the temperature of the fast cooling section can be 400-420 ℃, and the temperature of the overaging section can be 360-400 ℃.

In the embodiment of the application, the positive effect of controlling the temperature of the annealing soaking section to be 580-680 ℃ is that: compared with the conventional product, the annealing temperature is lower, on one hand, the low-temperature annealing can effectively inhibit the growth of crystal grains and improve the strength, thereby improving the compressive resistance. Meanwhile, the higher the annealing temperature is, the worse the anisotropic performance is, and as the battery shell is a symmetrical cylinder, the anisotropic performance can cause the phenomenon of lug making in the stamping process, and the problem of uneven wall thickness can also be caused, so that strict control is needed. On the other hand, after the nickel layer on the surface is annealed, the hardness is reduced, the nickel layer is easy to fall off in the subsequent stamping process, and an alloying bonding layer can be formed, so that the bonding force between the nickel layer and the steel matrix is increased, and the corrosion resistance is improved. Specifically, the soaking stage temperature may be 580 ℃, 600 ℃, 620 ℃, 640 ℃, 660 ℃, 680 ℃, etc. The positive effect of controlling the temperature of the slow cooling section to be 500-600℃ is that: ensuring the stable operation of the production process. Specifically, the temperature of the slow cooling section may be 500 ℃, 520 ℃, 540 ℃, 560 ℃, 580 ℃, 600 ℃, or the like. The positive effect of controlling the temperature of the quick cooling section to be 400-420℃ is that: the stable operation of the production process and the release of internal stress are ensured. Specifically, the rapid cooling section temperature may be 400 ℃, 410 ℃, 420 ℃, or the like. The positive effect of controlling the temperature of the overaging section to be 360-400℃ is that: the carbonaceous second phase particles are homogeneously dispersed. Specifically, the overaging stage temperature may be 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, etc.

The soaking time (T, s) and the soaking temperature (T, DEGC) are controlled to satisfy the following relation: positive effect of t= -0.979 t+ (710-730): because the alloying process of the nickel layer is sensitive to the annealing temperature and time, when the temperature is too high or the time is too long, the nickel layer grains are coarse, and the coating structure becomes loose. And when the temperature is too low, the alloying degree is insufficient, and the expected effect cannot be achieved. In order to obtain a better alloying coating, the technical staff of the invention find that the heat preservation time T is inversely proportional to the soaking temperature T, and the heat preservation time T and the soaking temperature T are optimal when the relation formula is required to be satisfied, and finally the thickness of the finally achieved alloying nickel layer is about 1.5 mu m.

In some embodiments, the flattening may be off-line or on-line flattening.

In some embodiments, the flat elongation may be 1.0 to 1.5%.

In the embodiment of the application, the positive effect of controlling the elongation of the leveling to be 1.0-1.5 percent is as follows: the surface appearance of the nickel-plated steel strip is more uniform through a leveling process, and the shape and the performance of the nickel-plated steel strip are more excellent. Specifically, the flat elongation may be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.

In some embodiments, the nickel layer and the steel substrate diffusion form an alloyed Ni-Fe layer having a thickness of 1.4 μm to 1.6 μm.

In the embodiment of the application, the nickel-plated steel strip has excellent corrosion resistance, good pressure resistance and forming performance and good anisotropism.

The nickel-plated steel strip prepared by the method has both the forming performance and the alloying performance of the nickel layer. The product has good mechanical property and surface quality, and good thickness and corrosion resistance of the nickel-iron alloy layer.

The preparation method of the low-carbon nickel-plated steel strip is realized based on the chemical components of the low-carbon nickel-plated steel strip, and the chemical components of the low-carbon nickel-plated steel strip can be specifically referred to the above embodiment.

The present application is further illustrated below in conjunction with specific examples. It should be understood that these examples are illustrative only of the present application and are not intended to limit the scope of the present application. The experimental procedures, which are not specified in the following examples, are generally determined according to national standards. If the corresponding national standard does not exist, the method is carried out according to the general international standard, the conventional condition or the condition recommended by the manufacturer.

In the embodiment of the application, molten iron is smelted to obtain the chemical components of the steel matrix of the nickel-plated steel strip in Table 1.

TABLE 1 chemical composition (wt%) of steel matrix of Nickel-plated Steel strip, balance Fe and unavoidable impurities

Based on the chemical components of the low-carbon nickel-plated steel strip, the embodiment of the application provides a preparation method of the low-carbon nickel-plated steel strip, which comprises the following steps:

s11, heating, rolling in stages, cooling after rolling and coiling the slab with the set chemical composition to obtain a hot rolled coil;

s21, pickling and cold continuous rolling are carried out on the hot rolled coil, and a chilled coil is obtained;

s31, carrying out nickel plating on the chilled coil, and controlling the thickness of the nickel layer of the nickel plating to obtain a nickel-plated coil;

s41, continuously annealing and flattening the nickel-plated coil, and controlling the flattening elongation to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section and the technological parameters of the soaking section are controlled; specifically, the preparation process parameters of the nickel-plated steel strip can be seen in table 2.

TABLE 2 preparation process parameters of Nickel-plated steel strip

For the nickel-plated steel strip pre-coated with the above examples and comparative examples, a test piece was cut at a plate width of 1/4 to conduct a conventional tensile test, and the strength was examined. The measurement of the nickel layer composition was performed by glow spectroscopy (GDS), mainly measuring the thickness of the alloy layer. And a neutral salt spray experiment is carried out according to GB-T/10125-2021 artificial atmosphere corrosion test salt spray test, and the corrosion resistance of the red rust area after 72 hours is evaluated. The results are shown in Table 3.

TABLE 3 Performance test results of Nickel pre-plated Steel strip

By the preparation method of the nickel preplating steel belt in the embodiment of the application, the mechanical property and the corrosion resistance of the embodiment 1-4 are better than those of the comparative example 1-2, and the strength and the anisotropy index are also better than those of the comparative example.

In addition, referring to the metallographic photograph of the nickel-plated steel strip provided in example 1 shown in fig. 2, the microstructure is ferrite and a small amount of pearlite, and the grain structure is uniform, which indicates that the nickel-plated steel strip has good punching performance and is beneficial to punching formation. In addition, referring to the 72-hour neutral salt spray experimental photograph of the nickel-plated steel strip provided in example 1 shown in fig. 3, the corrosion area is small, which indicates that the nickel-plated steel strip has good corrosion resistance.

The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the low-carbon nickel pre-plated steel strip is characterized by comprising the following steps of:

2. The method of claim 1, wherein the process parameters of the soaking section comprise: soaking temperature and soaking time; wherein,

3. The method according to claim 1 or 2, wherein the nickel-plated coil is continuously annealed and flattened, and the elongation of the flattening is controlled to obtain a nickel-plated steel strip; wherein the continuous annealing comprises a soaking section, and controlling the technological parameters of the soaking section, comprising:

4. The method of claim 1, wherein the flattened elongation is 1.0 to 1.5%.

5. The method of claim 1, wherein the nickel layer of nickel plating has a thickness of 2 μm to 4 μm.

6. The method according to claim 1, wherein the slab having the set chemical composition is heated, rolled in stages, cooled after rolling and coiled to obtain a hot rolled coil; wherein,

the coiling temperature is 500-650 ℃.

7. The method of claim 1, wherein the hot rolled coil is pickled and cold rolled to produce a chilled coil; wherein,

the rolling reduction of the cold continuous rolling is 75-85%.

8. The method of claim 1, wherein the setting the chemical composition comprises:

9. A low carbon nickel preplating steel strip, characterized in that said preplating steel strip is prepared by the method of any one of claims 1-8;

10. The low carbon nickel pre-plated steel strip according to claim 9, wherein the nickel layer and the steel substrate are diffusion formed into an alloyed Ni-Fe layer having a thickness of 1.4 μm to 1.6 μm.