Enamel steel sheet and method for manufacturing the same

Abstract

The application provides a kind of enamel steel plate and its preparation method, belong to the technical field of enamel steel plate production, the chemical composition of enamel steel plate includes by mass fraction: Alt: 0.03~0.15%, B: 0.004~0.015%, N: 0.01~0.03%; N mainly combines to form BN particle, BN has good stability, high temperature is not easy to dissolve, has the effect of stable promotion anti scale burst performance; Alt reacts with the remaining N to generate AlN, can play the role of grain refinement, hinder the grain growth during enameling, under the condition of specific process control, can make the strength of steel plate not decrease but increase at high temperature. Therefore, the enamel steel plate of the present application has good anti scale burst performance, and can solve the problem of strength decrease of existing enamel steel plate during high temperature enameling.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of enamel steel plate production, and in particular to an enamel steel plate and a preparation method thereof. BACKGROUND

[0002] The enamel steel plate is a composite material combining the properties of steel plate and enamel, which has the strength of steel plate and the double advantages of enamel, such as wear resistance, high temperature resistance, corrosion resistance, and bright color, and is widely used in light industry, household appliances, chemical industry, construction and other industries. The biggest problem in the production of enamel steel is the "scale explosion" phenomenon, which is similar to the fish scale peeling phenomenon. In addition to the scale explosion, another important problem faced by the enamel steel is that the strength of the steel plate will be significantly reduced during the high-temperature enameling process.

[0003] At present, the manufacturing method of cold-rolled enamel steel plate mostly adds alloy elements such as Cu, Nb, Ti, etc. in low-carbon steel to improve the anti-scale explosion performance of the steel, but this can only solve the scale explosion problem of the enamel product, and the problem of strength reduction of the steel plate during the enameling process has not been solved. SUMMARY

[0004] The embodiments of the present application provide an enamel steel plate and a preparation method thereof to solve the problem of strength reduction of the existing enamel steel plate during high-temperature enameling.

[0005] In a first aspect, the embodiments of the present application provide an enamel steel plate, and the chemical composition of the enamel steel plate includes, in terms of mass fraction: Alt: 0.03-0.15%, B: 0.004-0.015%, N: 0.01-0.03%.

[0006] Further, the mass fractions of N and B of the enamel steel plate satisfy a relationship formula one:

[0007] [N]-1.4×[B]≥0,

[0008] In the formula, [N] represents the mass fraction of N, and [B] represents the mass fraction of B.

[0009] Further, the mass fractions of N, B and Al of the enamel steel plate satisfy a relationship formula two:

[0010] [Al]-1.93×([N]-1.4×[B])≥0.02%, or

[0011] [Al]-1.93×([N]-1.4×[B])≥0.02% and [N]-1.4×[B]≥0,

[0012] In the formula, [Al] represents the mass fraction of Al, [N] represents the mass fraction of N, and [B] represents the mass fraction of B.

[0013] Further, the chemical composition of the enamel steel plate further includes, in terms of mass fraction, C≤0.07%, Si≤0.03%, and Mn: 0.2-0.6%.

[0014] In a second aspect, the embodiments of the present application provide a preparation method of the enamel steel plate of the first aspect, and the preparation method comprises the following steps:

[0015] The slab of the enamel steel plate is heated and rolled to obtain a hot-rolled plate.

[0016] The hot-rolled plate is subjected to laminar cooling and coiling to obtain a hot-rolled coil.

[0017] The hot-rolled coil is subjected to pickling and cold rolling to obtain a cold hard coil.

[0018] The cold hard coil is subjected to annealing and skin passing to obtain the enamel steel plate.

[0019] Further, the process parameters of the heating include a temperature of 1280-1380℃ and a furnace time of 200-300 min.

[0020] Further, the process parameters of the rolling include a roughing temperature of 1080-1180℃ and a finishing temperature of 880-970℃.

[0021] Further, the process parameters of the laminar cooling include a cooling rate of greater than 15℃ / s; and / or

[0022] The process parameters of the coiling include a temperature of 350-600℃.

[0023] Further, the process parameters of the cold rolling include a total reduction of 50%-85%; and / or

[0024] The annealing adopts a continuous annealing process, and the process parameters of the continuous annealing include an annealing soaking temperature of 780-850℃, a slow cooling temperature of 530-650℃, a fast cooling temperature of 400-420℃, and an overaging temperature of 350-380℃.

[0025] Further, the skin pass roll surface of the skin pass is a roughened roll surface with a roughness of greater than or equal to 4.0μm, and the process parameters of the skin pass include a skin pass elongation of 0.3-1.3%.

[0026] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0027] The embodiment of the present application provides a kind of enamel steel sheet, the chemical composition of the enamel steel sheet is as follows in mass fraction: Alt: 0.03~0.15%, B: 0.004~0.015%, N: 0.01~0.03%; the rest is iron and inevitable impurities;N is mainly combined with B to form BN particle, BN has good stability, high temperature is not easy to dissolve, has the effect of stable promotion anti-scale burst performance;Alt reacts with the remaining N to generate AlN, can play the role of grain refinement, hinder grain growth during enameling, under the cooperation of specific process control condition, can make the strength of steel plate not decline but rise at high temperature.Therefore, the enamel steel plate of the present application has good anti-scale burst performance, and can solve the problem of strength reduction of existing enamel steel plate during high temperature enameling. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings incorporated into the specification and forming part thereof show embodiments consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor under the premise of not paying the creative labor.

[0030] Figure 1 The second phase precipitation particle photo of the embodiment 1 of the present application is shown in the figure.

[0031] Figure 2 The result photo of electrostatic coating of the embodiment 1 of the present application is shown in the figure. DETAILED DESCRIPTION

[0032] The advantages and various effects of the present application will be more clearly presented by the following specific embodiments and examples. Those skilled in the art should understand that these specific embodiments and examples are used to illustrate the present application, not to limit the present application.

[0033] Throughout the specification, unless otherwise specifically indicated, the terms used herein are to be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs. If there is a contradiction, the present specification is preferred.

[0034] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by existing methods.

[0035] Enamel steel plate is a composite material with the properties of both steel plate and enamel, which has the strength of steel plate and the wear resistance, high temperature resistance, corrosion resistance and bright color of enamel, and is widely used in light industry, household appliances, chemical industry, construction and other industries. The biggest problem in the production of enamel steel is the easy occurrence of "scale explosion" phenomenon - a fish scale-like peeling phenomenon. In addition to scale explosion, another important problem faced by enamel steel is that the strength of the steel plate will be significantly reduced during the enameling process.

[0036] Currently, the manufacturing method of cold-rolled enamel steel plate mostly adds alloy elements such as Cu, Nb and Ti in low-carbon steel to improve the anti-scale explosion performance of the steel, but this can only solve the scale explosion problem of the enamel product, and the problem of strength reduction of the steel plate during enameling has not been solved.

[0037] The technical scheme provided by the embodiments of the present application solves the above technical problems, and the general idea is as follows:

[0038] In a first aspect, the embodiments of the present application provide an enamel steel plate, and the chemical composition of the enamel steel plate includes, in terms of mass fraction: C: ≤0.07%, Alt: 0.03-0.15%, B: 0.004-0.015%, N: 0.01-0.03%; and the rest is iron and unavoidable impurities.

[0039] In the present application, the chemical composition of the enamel steel plate, in addition to the above elements, is iron and unavoidable impurities. Among them, Alt generally refers to the total amount of aluminum, including acid-soluble aluminum (Als) and aluminum oxide (Alo).

[0040] The embodiments of the present application provide an enamel steel plate, and the chemical composition of the enamel steel plate includes, in terms of mass fraction: Alt: 0.03-0.15%, B: 0.004-0.015%, N: 0.01-0.03%; and the rest is iron and unavoidable impurities; N mainly combines with B to form BN particles, BN has good stability and is not easy to dissolve at high temperature, and has the effect of stably improving the anti-scale explosion performance; Alt reacts with the remaining N to form AlN, which can refine the grains and hinder the grain growth during enameling, and under the cooperation of specific process control conditions, the strength of the steel plate can be increased at high temperature. Therefore, the steel plate provided by the embodiments of the present application can solve the problem of strength reduction of the existing enamel steel plate during high-temperature enameling.

[0041] As an embodiment of the present application, the mass fraction of N and B of the enamel steel plate satisfies the relationship formula one:

[0042] [N]-1.4×[B]≥0,

[0043] In the formula, [N] represents the mass fraction of N, and [B] represents the mass fraction of B.

[0044] In the present application, the BN particles formed by the combination of N and B can play a role of anti-scaling performance, and the mass fraction of N and B is controlled to be N-1.4×B≥0, so that the element B can be completely fixed by N, thereby preventing the cast blank from generating crack defects.

[0045] As an embodiment of the present application, the mass fractions of N, B and Al of the enamel steel plate satisfy the following relationship:

[0046] [Al]-1.93×([N]-1.4×[B])≥0.02%, or

[0047] [Al]-1.93×([N]-1.4×[B])≥0.02% and [N]-1.4×[B]≥0,

[0048] In the formula, [Al] represents the mass fraction of Al, [N] represents the mass fraction of N, and [B] represents the mass fraction of B.

[0049] In the present application, Alt reacts with the remaining N to generate AlN, and since the solid solution N in the steel can cause aging and embrittlement defects, the quantitative relationship of Al-1.93×(N-1.4×B)≥0.02% between Alt, B and N can ensure sufficient Al.

[0050] As an embodiment of the present application, the chemical composition of the enamel steel plate further includes, in terms of mass fraction: C≤0.07%, Si≤0.03%, and Mn: 0.2-0.6%.

[0051] In the present application, the element C is oxidized to generate CO, CO2 and other gases during the enameling process, and excessive carbon content is easy to generate bubble defects and damage the surface quality of the enamel. On the other hand, carbon is the basis for improving strength and can directly strengthen the matrix through solid solution strengthening. Si is used as a deoxidizer to remove oxygen in the molten steel, and Si is a harmful element in the enamel steel, and an increase in the Si content can significantly reduce the adhesion of the enamel and damage the surface quality, so the Si content is selected to be controlled below 0.03%. Manganese reacts with sulfur to generate manganese sulfide, eliminating the brittleness of S, and Mn can improve the strength of the steel, but excessive Mn content is easy to cause banded structure, which is not conducive to the performance of the enamel. Generally speaking, sulfur is an impurity element in steel, which is easy to form brittle substances, and in the present application, S:≤0.012%; phosphorus is an impurity element, which is easy to segregate at the grain boundary, increasing the brittleness of the steel plate and damaging the formability of the steel plate, and is easy to generate bubbles and black spots during enameling, affecting the surface quality, and the phosphorus is controlled to be below 0.02% in the present application.

[0052] In a second aspect, the present application provides a preparation method of the enamel steel plate of the first aspect, and the preparation method comprises:

[0053] The slab of the enamel steel plate is heated and rolled to obtain a hot-rolled plate;

[0054] The hot-rolled plate is carried out laminar cooling and coiling to obtain a hot-rolled coil;

[0055] The hot-rolled coil is carried out pickling and cold rolling to obtain a cold hard coil;

[0056] The cold hard coil is carried out annealing and flattening to obtain an enamel steel plate.

[0057] In the application, by inhibiting the precipitation of AlN in the hot rolling and annealing process, and precipitating a large amount in the enameling process, on the one hand, the grain growth in the enameling process can be inhibited to cause softening, and on the other hand, the precipitation strengthening effect can be achieved, so that the strength of the steel plate after enameling not only does not decrease but also increases.

[0058] As an embodiment of the application, the process parameters of the heating include that the temperature is 1280-1380℃, and the furnace time is 200-300min.

[0059] In the application, by controlling the heating temperature and time, the full austenitization of the steel billet can be ensured, and the BN and AlN formed in the cast billet are fully dissolved, so that the controllable precipitation in the subsequent process can be achieved, and the expected effect can be achieved.

[0060] As an embodiment of the application, the process parameters of the rolling include that the opening rolling temperature is 1080-1180℃, and the finish rolling temperature is 880-970℃.

[0061] In the application, a high temperature is maintained in the whole rolling range, because the full solid solution temperature of BN is higher than that of AlN, in this temperature range, the BN particles are fully precipitated, which provides guarantee for the subsequent anti-scaling performance of the steel, and the precipitation amount of the AlN particles is limited, so as to precipitate in the subsequent enameling process.

[0062] As an embodiment of the application, the process parameters of the laminar cooling include that the cooling rate is greater than 15℃ / s, and / or the process parameters of the coiling include that the temperature is 350-600℃.

[0063] In the application, the rapid cooling and low-temperature coiling can inhibit the precipitation of AlN.

[0064] As an embodiment of the application, the process parameters of the cold rolling include that the total reduction rate is 50%-85%, and / or the annealing adopts a continuous annealing process, and the process parameters of the continuous annealing include that the annealing soaking temperature is 780-850℃, the slow cooling temperature is 530-650℃, the fast cooling temperature is 400-420℃, and the overaging temperature is 350-380℃.

[0065] In the present application, a higher cold rolling reduction is used to store sufficient distortion energy in the steel, which is beneficial to the development of texture and improves the forming property of the steel plate, and meanwhile, the recrystallization temperature is reduced, which is beneficial to the recrystallization after annealing. The high-temperature annealing process is used, and the temperature is close to the enameling temperature range, which is beneficial to reducing the strength reduction trend after enameling. The lower slow cooling temperature and fast cooling temperature provide a greater driving force for the precipitation of carbides in the steel, and the control of overaging temperature is beneficial to the precipitation of tertiary cementite, thereby further improving the anti-scaling performance.

[0066] As an embodiment of the present application, the smooth roll surface of the smoothing roll is a roughened roll surface, the roughness of the roll surface is greater than or equal to 4.0 μm, and the process parameters of the smoothing are as follows: the smoothing elongation is 0.3-1.3%.

[0067] In the present application, offline or online smoothing is used, and the principle of the smoothing process in the present application is to obtain a larger roughness of the plate surface under the condition of using a smaller smoothing elongation, and the rough surface structure is beneficial to improving the enamel adhesion. The work hardening of the smoothing provides a driving force for the strength reduction after enameling, and should be minimized. The surface roughness Ra of the cold hard coil in the present application is greater than or equal to 1.3 μm.

[0068] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and are not used to limit the scope of the present application. The experimental methods not specified in the following examples are generally determined according to the national standards. If there is no corresponding national standard, the international standard, the conventional condition, or the condition suggested by the manufacturer is used.

[0069] Example 1:

[0070] A kind of enamel steel plate and its preparation method, its characteristics include the following steps:

[0071] (1) slab preparation: after the molten iron is pretreated, the slab is obtained by converter smelting, RH / LF / CAS refining and continuous casting; wherein the chemical composition of the slab is shown in Table 1 in mass fraction;

[0072] (2) the slab is heated at 1280℃ for 280min, then rolled at 1080℃, and the finish rolling temperature is controlled at 880℃, to obtain a hot-rolled plate;

[0073] (3) the hot-rolled plate is laminar flow cooled at a cooling rate of 16℃ / s, and then coiled at 450℃, to obtain a hot-rolled coil;

[0074] (4) the hot-rolled coil is pickled and cold-rolled to obtain a cold hard coil; wherein the total reduction of cold rolling is 65%;

[0075] (5) the cold hard coil is subjected to continuous annealing process and skin pass, to obtain the enamel steel plate; wherein the annealing soaking temperature is 820 ℃, the slow cooling temperature is 620 ℃, the fast cooling temperature is 420 ℃, and the overaging temperature is 360 ℃; the skin pass roll surface of the skin pass is a roughened roll surface, the roll surface roughness is 4.0 μm, the skin pass elongation is 0.6%, and the skin pass result is that the surface roughness Ra of the finished steel coil is ≥1.3 μm.

[0076] Example 2

[0077] An enamel steel plate and a preparation method thereof, the features of which include the following steps:

[0078] (1) slab preparation: after pretreatment of molten iron, the slab is obtained through converter smelting, RH / LF / CAS refining, and continuous casting; wherein the chemical composition of the slab is shown in Table 1 in terms of mass fraction;

[0079] (2) the slab is heated at 1300 ℃ for 200 min, then rolled at 1170 ℃, and the finish rolling temperature is controlled at 960 ℃, to obtain a hot-rolled plate;

[0080] (3) the hot-rolled plate is subjected to laminar cooling at a cooling rate of 18 ℃ / s, and then coiled at 350 ℃, to obtain a hot-rolled coil;

[0081] (4) the hot-rolled coil is subjected to pickling and cold rolling, to obtain a cold hard coil; wherein the total reduction of the cold rolling is 75%;

[0082] (5) the cold hard coil is subjected to continuous annealing process and skin pass, to obtain the enamel steel plate; wherein the annealing soaking temperature is 780 ℃, the slow cooling temperature is 560 ℃, the fast cooling temperature is 410 ℃, and the overaging temperature is 380 ℃; the skin pass roll surface of the skin pass is a roughened roll surface, the roll surface roughness is 4.5 μm, the skin pass elongation is 1.2%, and the skin pass result is that the surface roughness Ra of the finished steel coil is ≥1.3 μm.

[0083] Example 3

[0084] An enamel steel plate and a preparation method thereof, the features of which include the following steps:

[0085] (1) slab preparation: after pretreatment of molten iron, the slab is obtained through converter smelting, RH / LF / CAS refining, and continuous casting; wherein the chemical composition of the slab is shown in Table 1 in terms of mass fraction;

[0086] (2) the slab is heated at 1370 ℃ for 300 min, then rolled at 1100 ℃, and the finish rolling temperature is controlled at 920 ℃, to obtain a hot-rolled plate;

[0087] (3) the hot-rolled plate is subjected to laminar cooling at a cooling rate of 16 ℃ / s, and then coiled at 540 ℃, to obtain a hot-rolled coil;

[0088] (4) the hot-rolled coil is pickled and cold-rolled to obtain a cold-hard coil; wherein the total reduction of cold-rolling is 83%;

[0089] (5) the cold-hard coil is subjected to a continuous annealing process and skin-passing to obtain the enamel steel plate; wherein the annealing soaking temperature is 820℃, the slow cooling temperature is 620℃, the fast cooling temperature is 420℃, and the overaging temperature is 350℃; the skin-passing roll surface is a roughened roll surface, the roll surface roughness is 4.5μm, the skin-passing elongation is 0.8%, and the skin-passing result is that the surface roughness Ra of the finished steel coil is ≥1.3μm.

[0090] Example 4:

[0091] An enamel steel plate and a preparation method thereof, the features of which include the following steps:

[0092] (1) slab preparation: after pretreatment of molten iron, a slab is obtained through converter smelting, RH / LF / CAS refining, and continuous casting; wherein the chemical composition of the slab is shown in Table 1 in terms of mass fraction;

[0093] (2) the slab is heated at 1290℃ for 210min, and then rolled at 1130℃, with the finish rolling temperature controlled at 900℃, to obtain a hot-rolled plate;

[0094] (3) the hot-rolled plate is subjected to laminar cooling at a cooling rate of 20℃ / s, and then coiled at 430℃ to obtain a hot-rolled coil;

[0095] (4) the hot-rolled coil is pickled and cold-rolled to obtain a cold-hard coil; wherein the total reduction of cold-rolling is 60%;

[0096] (5) the cold-hard coil is subjected to a continuous annealing process and skin-passing to obtain the enamel steel plate; wherein the annealing soaking temperature is 840℃, the slow cooling temperature is 630℃, the fast cooling temperature is 400℃, and the overaging temperature is 375℃; the skin-passing roll surface is a roughened roll surface, the roll surface roughness is 5.0μm, the skin-passing elongation is 0.3%, and the skin-passing result is that the surface roughness Ra of the finished steel coil is ≥1.3μm.

[0097] Comparative Example 1:

[0098] The chemical composition of the slab is shown in Table 1 in terms of mass fraction, the heating temperature in Example 1 is changed to 1180℃, the heating time is changed to 190min, the starting rolling temperature is changed to 1060℃, the coiling temperature is changed to 550℃, the total reduction of cold-rolling is changed to 65%, the annealing soaking temperature is changed to 730℃, the slow cooling temperature is changed to 660℃, the fast cooling temperature is changed to 440℃, the overaging temperature is changed to 400℃, the roll surface roughness is changed to 3.0μm, and the skin-passing elongation is changed to 0.8%, and the rest is the same as in Example 1.

[0099] Comparative Example 2:

[0100] The chemical composition of the slab is shown in Table 1 in mass fraction, the heating temperature in Example 1 is changed to 1140℃, the heating time is changed to 200min, the opening rolling temperature is changed to 1070℃, the coiling temperature is changed to 730℃, the total reduction of cold rolling is changed to 77%, the annealing soaking temperature is changed to 760℃, the slow cooling temperature is changed to 680℃, the rapid cooling temperature is changed to 420℃, the overaging temperature is changed to 383℃, the roll surface roughness is changed to 2.4μm, the flat extension rate is changed to 0.7%, and the rest is the same as Example 1.

[0101] Table 1 Chemical composition of the slab of the examples and comparative examples (wt. %)

[0102] C Si Mn S P Alt B N Example 1 0.035 0.02 0.20 0.006 0.012 0.039 0.006 0.011 Example 2 0.063 0.01 0.14 0.012 0.017 0.144 0.014 0.027 Example 3 0.015 0.03 0.55 0.005 0.015 0.087 0.012 0.018 Example 4 0.003 0.01 0.13 0.009 0.009 0.072 0.015 0.028 Comparative Example 1 0.052 0.01 0.3 0.010 0.0013 0.037 0.002 0.003 Comparative Example 2 0.003 0.01 0.14 0.012 0.0010 0.037 - 0.014

[0103] The steel plates of the examples and comparative examples are tested for performance: samples are cut at 1 / 4 of the plate width for conventional tensile test, and hydrogen permeation sample is sampled and TH value of the steel plate is measured and calculated at the same time (TH value is measured and calculated according to national standard GB / T 29515-2013 “Cold-rolled steel plate for enamel use, test method for hydrogen permeation”).

[0104] 5 samples of the steel plates of each example and comparative example are taken at different positions for small sample enameling in the laboratory, the enameling method is electrostatic dry powder enameling, the scale explosion phenomenon is observed, and the samples after enameling are taken out of the enamel layer for tensile test, and the change of strength is observed. The test results are shown in Table 4.

[0105] Table 4 TH value and mechanical properties of the steel plates of the examples and comparative examples

[0106]

[0107]

[0108] In summary, the example of the present application provides an enamel steel plate, which adopts a large number of BN and AlN precipitated particles in the steel as hydrogen traps. Compared with other technical enamel steels which use TiC and Fe3C as hydrogen traps, the stability is good, and the enamel steel is not easy to dissolve during enameling, and will not cause the anti-scale explosion performance to decrease after enameling. And the AlN is inhibited from precipitating during hot rolling and annealing through process control, so that it precipitates during enameling, and the AlN inhibits grain growth during enameling on the one hand, and has the effect of precipitation strengthening on the other hand. The annealing process adopts high temperature annealing and small flat extension rate process, which reduces the driving force of grain growth during enameling, and the multiple effects make the strength of the enamel steel plate increase after enameling.

[0109] It should be understood that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0110] It should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the term "and / or" as used herein is merely a description of 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.

[0111] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An enamel steel sheet, characterized by, The chemical composition of the enamel steel plate is as follows in mass fraction: C≤0.07 %, Si≤0.03 %, Mn: 0.2-0.6 %, Alt: 0.03-0.15 %, B: 0.004-0.015 %, N: 0.01-0.03 %, and the rest is iron and inevitable impurities; the mass fractions of N and B of the enamel steel plate satisfy a relationship formula one: [N]-1.4×[B]≥0; The mass fractions of N, B and Al of the enamel steel plate satisfy a relationship formula two: [Al]-1.93×([N]-1.4×[B])≥0.02 %; In the formula, [Al] represents the mass fraction of Al, [N] represents the mass fraction of N, and [B] represents the mass fraction of B; The preparation process of the enamel steel plate comprises heating, rolling, laminar cooling, coiling, pickling, cold rolling, annealing and skin passing of a slab, wherein the process parameters of heating comprise: a temperature of 1280-1380 ℃, and a furnace time of 200-300 min; the process parameters of rolling comprise: a roughing temperature of 1080-1180 ℃, a finishing temperature of 880-970 ℃, and a coiling temperature of 350-540 °C; the continuous annealing process is adopted for annealing, and the process parameters of the continuous annealing process comprise: an annealing soaking temperature of 780-850 ℃, a slow cooling temperature of 530-650 ℃, a fast cooling temperature of 400-420 ℃, and a overaging temperature of 350-380 ℃; the skin passing roller surface is a roughened roller surface with a roughness of ≥4.0 μm, and the process parameters of skin passing comprise: a skin passing elongation of 0.3-1.3 %.

2. A method of producing a vitreous steel sheet as claimed in claim 1, characterized in that, The preparation method comprises: heating and rolling a slab of the enamel steel plate to obtain a hot-rolled plate; performing laminar cooling and coiling on the hot-rolled plate to obtain a hot-rolled coil; performing pickling and cold rolling on the hot-rolled coil to obtain a cold hard coil; performing annealing and skin passing on the cold hard coil to obtain the enamel steel plate; wherein the process parameters of heating comprise: a temperature of 1280-1380 ℃, and a furnace time of 200-300 min; the process parameters of rolling comprise: a roughing temperature of 1080-1180 ℃, a finishing temperature of 880-970 ℃, and a coiling temperature of 350-540 °C; the continuous annealing process is adopted for annealing, and the process parameters of the continuous annealing process comprise: an annealing soaking temperature of 780-850 ℃, a slow cooling temperature of 530-650 ℃, a fast cooling temperature of 400-420 ℃, and a overaging temperature of 350-380 ℃; the skin passing roller surface is a roughened roller surface with a roughness of ≥4.0 μm, and the process parameters of skin passing comprise: a skin passing elongation of 0.3-1.3 %.

3. The preparation method according to claim 2, characterized in that, The process parameters of laminar cooling comprise: a cooling rate of greater than 15 ℃ / s.

4. The preparation method according to claim 2, characterized in that, The process parameters of cold rolling comprise: a total reduction of 50-85 %.

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