A method for producing a tinplate

Abstract

The application relates to the technical field of steel production, in particular to a preparation method of a tin-plated plate. The preparation method of the tin-plated plate comprises the following steps: hot-rolling a casting blank containing a set chemical composition, then coiling to obtain a hot-rolled coil with a first thickness; under the condition of a set reduction ratio of the acid rolling, performing first-stage acid rolling on the hot-rolled coil with the first thickness through an acid rolling machine 1-4# rack, so that the thickness variation of the hot-rolled coil is in a set range; under the condition of a set roughness of a rolling roller of an acid rolling machine 5# rack, performing second-stage acid rolling on the hot-rolled coil after the first-stage acid rolling through the acid rolling machine 5# rack in a roller emptying mode, so that the surface roughness of the hot-rolled coil after the first-stage acid rolling is improved; performing cover annealing, flattening and tin plating on the hot-rolled coil after the second-stage acid rolling, and obtaining a tin-plated plate. The application solves the technical problems that the tin-plated plate has a low roughness and obvious rolling lines.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of steel production, and in particular to a preparation method of a tin-plated plate. BACKGROUND

[0002] The tin-plated plate is a cold-rolled low-carbon steel plate or strip plated with tin on both sides through electroplating, and is currently applied to emerging fields such as home decoration, household appliance shells and dustproof covers of electrical equipment.

[0003] At present, a four-high double-stand temper mill and a wet tempering process are used, the rolling force is up to 5-6 MN, the roughness replication effect is poor, the roughness after plating can only reach about 0.7 microns, the plate shape is difficult to guarantee under a large rolling force, and the rolling lines are extremely obvious, which cannot meet the current demand. SUMMARY

[0004] The application provides a tin-plated plate and a preparation method thereof, so as to solve the technical problem of low roughness and obvious rolling lines of the tin-plated plate.

[0005] In a first aspect, the application provides a preparation method of a tin-plated plate, which comprises the following steps:

[0006] Hot-rolling a casting blank containing a set chemical composition to obtain a hot-rolled coil with a first thickness;

[0007] Under the condition of a set rolling reduction rate, performing first-stage acid rolling on the hot-rolled coil with the first thickness by an acid rolling mill 1-4# rack to make the thickness variation of the hot-rolled coil be in a set range;

[0008] Under the condition of a set roughness of a rolling mill 5# rack, performing second-stage acid rolling on the hot-rolled coil after the first-stage acid rolling by the rolling mill 5# rack in a rolling mill emptying mode to improve the surface roughness of the hot-rolled coil after the first-stage acid rolling;

[0009] Performing cover annealing on the hot-rolled coil after the second-stage acid rolling to obtain an annealed coil;

[0010] Performing tempering on the annealed coil, and then performing tin plating to obtain a tin-plated plate.

[0011] Optionally, the first thickness is 1.50 mm-1.70 mm.

[0012] Optionally, the rolling reduction rate of the acid rolling is greater than or equal to 88%.

[0013] Optionally, the roughness of the rolling mill 5# rack is 3.6 microns-4.2 microns.

[0014] Optionally, the tempering comprises the following steps:

[0015] The roughness of the roll of the first pass of the temper mill 1 is set to 2.6-3.7 microns.

[0016] The roughness of the roll of the first pass of the temper mill 1 is set to 2.6-3.7 microns.

[0017] The roughness of the roll of the first pass of the temper mill 1 is set to 2.6-3.7 microns.

[0018] Optionally, the elongation of the roll of the first pass of the temper mill 1 is set to 0.8-1.3%.

[0019] Optionally, the elongation of the roll of the first pass of the temper mill 1 is set to 0.8-1.3%.

[0020] Optionally, the hot rolling includes reheating, finish rolling and coiling.

[0021] The temperature of the reheating is 1170-1240 degrees Celsius.

[0022] The temperature of the finish rolling is 850-890 degrees Celsius.

[0023] The temperature of the coiling is 550-590 degrees Celsius.

[0024] Optionally, the temperature of the batch annealing is 585-595 degrees Celsius.

[0025] Optionally, the chemical composition is set to C, Si, Mn, P, S, Als, N, the rest is Fe and inevitable impurities; wherein,

[0026] C: 0.05-0.07% by weight; Si: ≤0.03% by weight; Mn: 0.3-0.4% by weight; P: ≤0.015% by weight; S: ≤0.015% by weight; Als: 0.025-0.055% by weight; N: 0.003-0.006% by weight.

[0027] The above technical solution provided by the embodiments of the present application has the following advantages compared with the prior art:

[0028] The method provided by the embodiments of the present application reduces the target thickness of the hot rolling, and sets the reduction rate of the pickling mill 1-4, so that the thickness variation of the hot rolling is within the set range.

[0029] Under the condition of setting roughness of the 5# stand of the skin pass mill 5, the hot-rolled coil after the first stage skin pass is subjected to the second stage skin pass by the 5# stand of the skin pass mill 5 in the roll-skipping mode, so as to improve the surface roughness of the hot-rolled coil after the first stage skin pass;

[0030] Secondly, the annealed coil is subjected to the first stage skin pass by the large-roughness super-precision grinding roller of the 1# stand of the skin pass mill 1, so as to improve the roughness of the annealed coil; the annealed coil is subjected to the second stage skin pass by the 2# stand of the skin pass mill 2 in the roll-skipping mode, so as to weaken the surface rolling lines of the annealed coil with the second roughness.

[0031] In conclusion, the tin-plated plate prepared by the method has a roughness of 0.8 μm or more, a clear grain feeling and no obvious rolling lines. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced hereinafter. Obviously, those skilled in the art can obtain other drawings from these drawings without any creative effort.

[0034] Figure 1 A flowchart of a tin-plated plate method provided by the embodiments of the present application;

[0035] Figure 2 A micro-morphology diagram of a tin-plated plate provided by the embodiment 1 of the present application;

[0036] Figure 3 A micro-morphology diagram of a tin-plated plate provided by the embodiment 2 of the present application;

[0037] Figure 4 A micro-morphology diagram of a tin-plated plate provided by the embodiment 3 of the present application;

[0038] Figure 5 A micro-morphology diagram of a tin-plated plate provided by the embodiment 4 of the present application;

[0039] Figure 6 A micro-morphology diagram of a tin-plated plate provided by the comparative example 5 of the present application;

[0040] Figure 7 A micro-morphology diagram of a tin-plated plate provided by the comparative example 6 of the present application;

[0041] Figure 8 A micro-morphology diagram of a tin-plated plate provided by the comparative example 7 of the present application. DETAILED DESCRIPTION

[0042] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0043] Unless otherwise specifically indicated, all the various raw materials, reagents, instruments and equipment and the like used in the present application can be purchased from the market or can be prepared by the existing method.

[0044] In a first aspect, the present application provides a method for preparing a tin-plated plate, please see Figure 1 , the method comprises:

[0045] S1, a cast blank containing a set of chemical composition is hot-rolled to obtain a hot-rolled coil with a first thickness;

[0046] S2, under the condition of a set of rolling reduction ratio, the hot-rolled coil with the first thickness is subjected to a first-stage acid rolling by an acid rolling mill 1-4# rack to make the thickness variation of the hot-rolled coil in a set range;

[0047] S3, under the condition of a set of roughness of the rolling mill 5# rack, the hot-rolled coil after the first-stage acid rolling is subjected to a second-stage acid rolling by the rolling mill 5# rack in a way of rolling mill emptying to improve the surface roughness of the hot-rolled coil after the first-stage acid rolling;

[0048] S4, the hot-rolled coil after the second-stage acid rolling is subjected to a cover annealing to obtain an annealed coil;

[0049] S5, the annealed coil is subjected to a flattening and then a tin plating to obtain a tin-plated plate.

[0050] In the embodiments of the present application, the hot-rolled coil is subjected to a first-stage acid rolling by the acid rolling mill 1-4# rack, which has a positive effect of ensuring the thickness of the steel; secondly, the roughness of the rolling mill 5# rack is set to subject the hot-rolled coil to a second-stage acid rolling, which has a positive effect of improving the roughness replication degree and improving the surface roughness of the cold hard plate; if the acid rolling mill 1-5 rack is used for the conventional rolling process, the roughness of the cold hard plate is too small to a certain extent, which cannot guarantee the roughness of the finished coil.

[0051] In some embodiments, the first thickness is 1.50mm-1.70mm.

[0052] In the embodiments of the present application, the positive effect of setting the hot rolling target thickness to 1.50mm-1.70mm is to reduce the lower limit of the pickling rolling reduction rate as much as possible, and to reduce the difficulty of four-stand rolling before pickling. When the target thickness is too thin, the adverse effect is that the iron oxide scale is not easy to control, and the surface quality is deteriorated; when the target thickness is too thick, the adverse effect is that the load of four-stand rolling before pickling is too large, and the finished product thickness is thick. Specifically, the hot rolling target thickness can be 1.5mm, 1.52mm, 1.54mm, 1.56mm, 1.58mm, 1.60mm, 1.62mm, 1.64mm, 1.66mm, 1.68mm, 1.70mm, etc.

[0053] In some embodiments, the pickling rolling reduction rate is ≥88%.

[0054] In the embodiments of the present application, the positive effect of the pickling rolling reduction rate ≥88% is that the grains can be broken, the annealing grains are refined, the carbides are promoted to precipitate from the grains during annealing, and the strength is improved. When the value of the pickling rolling reduction rate is too small, the adverse effect is that the grains cannot be broken due to the too low pickling rolling reduction rate, so that the carbides cannot be promoted to precipitate from the grains during annealing, and the strength cannot be improved. In the embodiments of the present application, the 1-5# stand rolling reduction rate distribution is 48%, 47%, 35%, 30%, and 4% in turn.

[0055] In some embodiments, the roughness of the 5# stand rolling mill is set to 3.6μm-4.2μm.

[0056] In the embodiments of the present application, the 5# stand rolling mill can effectively improve the roughness replication degree and improve the surface roughness of the cold hard plate. Specifically, the roughness of the 5# stand rolling mill of the pickling mill can be 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4.0μm, 4.1μm, 4.2μm, etc.

[0057] In some embodiments, the skin passing includes:

[0058] The rolling mill 1# stand rolling mill is subjected to superfinishing treatment to obtain a superfinishing rolling mill 1# stand rolling mill;

[0059] Under the condition of setting the roughness and elongation of the superfinishing rolling mill 1# stand rolling mill, the annealed coil is subjected to first stage skin passing by the superfinishing rolling mill 1# stand rolling mill to improve the roughness of the annealed coil;

[0060] The first stage skin passed annealed coil is subjected to second stage skin passing by the rolling mill 2# stand rolling mill in a rolling mill emptying mode to weaken the surface rolling lines of the first stage skin passed annealed coil.

[0061] In the embodiment, the 1# stand of the skin pass mill adopts large-roughness super-finished roughening roller. The large-roughness roughening roller is used to further improve the roughness of the annealed coil. The super-finished roughening roller is used to make the distribution of the micro-peak and valley on the surface of the steel plate more uniform. The 2# stand of the skin pass mill is used to weaken the rolling lines on the surface of the steel plate under the current wet skin pass process. If the 1# stand adopts a low-roughness smooth roller, the roughness of the annealed coil will be less improved or even decreased. If the 1# stand adopts a non-super-finished roughening roller, the distribution of the micro-peak and valley on the surface of the steel plate will be uneven. The 1# and 2# stands are simultaneously rolled, which will produce obvious rolling lines.

[0062] In some embodiments, the extension rate of the super-finished roller of the 1# stand of the skin pass mill is 0.8% to 1.3%.

[0063] In the embodiment, the extension rate of the skin pass is 0.8% to 1.3%. The positive effect is to ensure the rolling load and the shape of the steel plate and to control the final yield strength. If the extension rate is too large, the shape of the steel plate will be out of control. If the extension rate is too small, the yield strength of the steel substrate will be too low, which will increase the production difficulty. Specifically, the extension rate of the skin pass can be 0.80%, 0.85%, 0.90%, 0.95%, 1.0%, 1.3%, etc.

[0064] In some embodiments, the roughness of the super-finished roller of the 1# stand of the skin pass mill is 2.6 μm to 3.7 μm. The positive effect is to ensure the replication rate of the roughness so as to obtain the roughness of the annealed coil. If the roughness of the roller is too large, the grinding difficulty and the roller replacement time will be increased, which will affect the production rhythm and the cost. If the roughness of the roller is too small, the roughness of the annealed coil will be too small, which cannot meet the demand. Specifically, the roughness of the super-finished roller of the 1# stand of the skin pass mill can be 2.6 μm, 2.8 μm, 3.0 μm, 3.2 μm, 3.4 μm, etc.

[0065] In some embodiments, the hot rolling includes reheating, finish rolling and coiling;

[0066] The temperature of the reheating is 1170 ℃ to 1240 ℃;

[0067] The temperature of the finish rolling is 850 ℃ to 890 ℃;

[0068] The temperature of the coiling is 550 ℃ to 590 ℃.

[0069] In the embodiments of the present application, the positive effect of controlling the reheating temperature to be 1170-1240°C is to fully austenitize the slab and fully solid-solve the N element, while controlling the heating cost. When the temperature is too large, the negative effect is that the high temperature will increase the heating cost; when the temperature is too small, the negative effect is that the low temperature will not be able to fully convert the austenite, affecting the strength of the steel matrix. Specifically, the reheating temperature can be 1170°C, 1180°C, 1190°C, 1200°C, 1210°C, 1230°C, 1240°C, etc.

[0070] The positive effect of controlling the finishing temperature to be 850-890°C is to use high-temperature finishing to make the finish rolling in the austenite zone, avoiding the occurrence of mixed crystal phenomenon. When the temperature is too large, the negative effect is that the high temperature increases the thickness of the surface iron scale of the steel matrix, deteriorating the surface quality; when the temperature is too small, the negative effect is that the finish rolling cannot be in the austenite zone, and mixed crystal phenomenon is prone to occur, the edge and center performance of the steel matrix is uneven, resulting in a decrease in the strength of the tin-plated plate. Specifically, the finishing temperature can be 850°C, 855°C, 860°C, 865°C, 870°C, 875°C, 880°C, 885°C, 890°C, etc.

[0071] The positive effect of controlling the coiling temperature to be 550-590°C is to inhibit the precipitation of AlN and promote the precipitation of carbides in the grain, thereby reducing the difficulty of the precipitation of carbides in the grain during the continuous annealing stage, and improving the stability of the mechanical properties of the strip steel. When the temperature is too large, the negative effect is that the high temperature generates too much coarse-grained carbide, which will precipitate at the grain boundary, affecting the surface quality of the steel matrix; when the temperature is too small, the negative effect is that the low temperature will inhibit the precipitation of carbides, and the too low coiling temperature is difficult to industrialize. Specifically, the coiling temperature can be 550°C, 555°C, 560°C, 565°C, 570°C, 575°C, 580°C, 585°C, 590°C, etc.

[0072] In some embodiments, the temperature of the batch annealing is 585-595°C.

[0073] In the embodiments of the present application, the positive effect of controlling the temperature of the batch annealing to be 585-595°C is to obtain a reasonable grain size. A temperature that is too large can cause coarse grains and reduce the performance of the finished product; a temperature that is too small can cause excessive grain refinement, and even incomplete recrystallization, reducing the plasticity. Specifically, the temperature of the batch annealing can be 585°C, 586°C, 587°C, 588°C, 589°C, 590°C, 591°C, 592°C, 593°C, 594°C, 595°C, etc.

[0074] In some embodiments, the set chemical composition is C, Si, Mn, P, S, Als, N, the rest is Fe and inevitable impurities; wherein,

[0075] C: 0.05wt%~0.07wt%; Si: ≤0.03wt%; Mn: 0.3wt%~0.4wt%; P: ≤0.015wt%; S: ≤0.015wt%; Als: 0.025wt%~0.055wt%; N: 0.003wt%~0.006wt%.

[0076] In the embodiments of the present application, the positive effect of controlling the content of C to be 0.05wt%~0.07wt% is that C is a relevant element of strength, and an appropriate amount of C element can provide sufficient strength of the tin-plated plate prepared from the steel matrix. When the value of the content is too large, the adverse effect is that too high C element will lead to slab cracks; when the value of the content is too small, the adverse effect is that too low C element content will lead to insufficient strength of the slab. Specifically, the content of C can be 0.05wt%, 0.052wt%, 0.054wt%, 0.056wt%, 0.058wt%, 0.06wt%, 0.062wt%, 0.064wt%, 0.066wt%, 0.068wt%, 0.07wt% and the like.

[0077] The positive effect of controlling the content of Si to be ≤0.03wt% is to improve the surface quality of the steel matrix. When the value of the content is too large, the adverse effect is that too high Si will increase the iron oxide scale, affecting the surface quality of the steel matrix. Specifically, the content of Si can be 0.03wt%, 0.01wt%, 0.015wt%, 0.02wt%, 0.025wt% and the like.

[0078] The positive effect of controlling the content of Mn to be 0.3wt%~0.4wt% is that Mn can form various solid solutions with C and N as solid solution strengthening elements, thereby improving the strength and elongation of the tin-plated plate prepared from the steel matrix. When the value of the content is too large, the adverse effect is that too high Mn element will lead to high alloy cost; when the value of the content is too small, the adverse effect is that too low Mn element content will lead to insufficient solid solution, resulting in insufficient strength of the tin-plated plate prepared from the steel matrix, affecting the elongation of the tin-plated plate prepared from the steel matrix. Specifically, the content of Mn can be 0.31wt%, 0.32wt%, 0.34wt%, 0.35wt%, 0.36wt%, 0.37wt%, 0.38wt%, 0.39wt%, 0.40wt% and the like.

[0079] The positive effect of controlling the content of P to be less than or equal to 0.015% by weight is to avoid the decrease of plasticity. When the content is too large, the adverse effect is that the high content of P will increase the cold working brittleness. Specifically, the content of P can be 0.015%, 0.001%, 0.013%, 0.014%, 0.012% by weight, etc.

[0080] The positive effect of controlling the content of S to be less than or equal to 0.015% by weight is to avoid the decrease of plasticity of the steel matrix and reduce the generation of MnS inclusions. When the content is too large, the adverse effect is that the plasticity of the steel matrix decreases, the number of MnS inclusions increases, and the performance of the steel matrix is affected. Specifically, the content of S can be 0.015%, 0.001%, 0.013%, 0.014%, 0.012% by weight, etc.

[0081] The positive effect of controlling the content of Als to be 0.025%-0.055% by weight is that Al can form fine-grained carbides, which can improve the strength of the tin-plated plate prepared from the steel matrix. When the content is too large, the adverse effect is that AlN precipitates, causing surface defects of the tin-plated plate prepared from the steel matrix; when the content is too small, the adverse effect is that too low Al cannot form enough AlN solid solution, which affects the strength of the steel matrix. Specifically, the content of Als can be 0.025%, 0.03%, 0.035%, 0.04%, 0.045%, 0.05%, 0.055% by weight, etc.

[0082] The positive effect of controlling the content of N to be 0.003%-0.006% by weight is that N has a strong solid solution strengthening effect in the tin-plated plate prepared from the steel matrix, and can be used as a solid solution strengthening element. Appropriate content of N will form enough solid solution to improve the strength of the tin-plated plate prepared from the steel matrix. When the content is too large, the adverse effect is that too high N is easy to generate a large amount of solid solution, and increase the recrystallization temperature, and the excess solid solution will precipitate, which will form surface defects; when the content is too small, the adverse effect is that not enough solid solution N is generated, which makes the strengthening contribution of N component insufficient, and the strength of the finished coil is low. Specifically, the content of N can be 0.003%, 0.0035%, 0.004%, 0.0045%, 0.005%, 0.0055%, 0.006% by weight, etc.

[0083] The tin-plated plate is realized based on the above-mentioned preparation method of the tin-plated plate. The specific steps of the preparation method of the tin-plated plate can refer to the above-mentioned embodiments. Since the tin-plated plate adopts part or all of the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0084] The present application is further described in conjunction with the following specific examples. It should be understood that these examples are only intended to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods in the following examples, if not otherwise specified, are generally determined according to the national standards. If there is no corresponding national standard, the general international standards, the conventional conditions, or the conditions suggested by the manufacturers are used.

[0085] Table 1 Experimental parameters of the 5# stand of the pickling mill and the 1# stand of the temper mill.

[0086]

[0087] Table 2 Chemical composition of the tin-plated steel (wt.%), the rest being Fe and unavoidable impurities.

[0088] Serial number C Si Mn P S Als N Example 1 0.050 0.03 0.30 0.015 0.015 0.025 0.0030 Example 2 0.070 0.01 0.40 0.008 0.005 0.034 0.0056 Example 3 0.061 0.01 0.34 0.008 0.007 0.045 0.0060 Example 4 0.054 0.01 0.38 0.009 0.009 0.035 0.0048 Comparative Example 1 0.063 0.02 0.32 0.010 0.012 0.029 0.0037 Comparative Example 2 0.055 0.03 0.33 0.012 0.011 0.055 0.0046 Comparative Example 3 0.067 0.03 0.33 0.011 0.010 0.0505 0.0039

[0089] Table 3 Process parameters for preparing the tin-plated steel.

[0090]

[0091] Table 4 Roughness of the finished product sample of the tin-plated steel.

[0092] Serial number Roughness (pm) Example 1 0.98 Example 2 1.1 Example 3 0.93 Example 4 0.85 Comparative Example 1 0.58 Comparative Example 2 0.63 Comparative Example 3 0.74

[0093] Roughness test method: measured according to GB / T 2523.

[0094] From Table 3, it can be seen that the roughness of the finished product cannot meet the requirements when the 5# stand of the pickling mill uses a smooth roll. Through Examples 1-4, the roughness of the finished product is obviously improved when the 5# stand of the pickling mill uses a rough roll, and the roughness of the 1# stand of the temper mill is also beneficial to improving the roughness of the finished product roll. Figures 2 to 8 From the micro-morphology graph, it is found that the distribution of the peaks and valleys of the surface of the finished product of Example 4 is the most uniform, and the effect of removing the rolling marks is the best.

[0095] Various embodiments of the present application can exist in a range of forms; it should be understood that the description in the form of a range is merely for the convenience and brevity, and should not be understood as a hard limitation on the scope of the present application; therefore, it should be considered that the range described has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description 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, regardless of the range. In addition, whenever a numerical range is indicated in this text, it means that any cited number (fraction or integer) within the indicated range is included.

[0096] In the present application, the orientation words such as "upper" and "lower" are specifically the directions of the drawing surface in the drawings unless otherwise stated. In addition, in the description of the present application, the terms "comprise", "contain" and the like mean "comprise but not limited to". In the present text, the relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. In the present text, the "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent: the case of A alone, the case of A and B existing at the same time, and the case of B alone. Wherein A, B can be singular or plural. In the present text, "at least one" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of these items, including any combination of single item or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent: a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b, c can be single or multiple.

[0097] The above description is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for producing a tin-plated sheet, characterized by, The method comprises: casting slabs with a set chemical composition are hot-rolled to obtain hot-rolled coils with a first thickness; under the condition of a set reduction rate of the pickling mill, the hot-rolled coils with the first thickness are subjected to first-stage pickling by the 1-4# rack of the pickling mill, so that the thickness variation of the hot-rolled coils is within a set range; under the condition of a set roughness of the 5# rack of the pickling mill, the hot-rolled coils after the first-stage pickling are subjected to second-stage pickling by the 5# rack of the pickling mill in a roll-skipping mode, so as to increase the surface roughness of the hot-rolled coils after the first-stage pickling; the hot-rolled coils after the second-stage pickling are subjected to batch annealing to obtain annealed coils; the annealed coils are subjected to temper rolling, then tinned to obtain tinned sheets.

2. The method of claim 1, wherein, The first thickness is 1.50mm-1.70mm.

3. The method of claim 1, wherein, The reduction rate of the pickling is ≥88%.

4. The method of claim 1, wherein, The roughness of the 5# rack of the pickling mill is 3.6μm-4.2μm.

5. The method of claim 1, wherein, The temper rolling comprises: the roll of the 1# rack of the temper mill is subjected to superfinishing to obtain a superfinishing roll of the 1# rack of the temper mill; under the condition of a set roughness and elongation of the superfinishing roll of the 1# rack of the temper mill, the annealed coils are subjected to first-stage temper rolling by the superfinishing roll of the 1# rack of the temper mill, so as to increase the roughness of the annealed coils; the annealed coils after the first-stage temper rolling are subjected to second-stage temper rolling by the roll of the 2# rack of the temper mill in a roll-skipping mode, so as to weaken the surface rolling lines of the annealed coils after the first-stage temper rolling.

6. The method of claim 5, wherein, The elongation of the superfinishing roll of the 1# rack of the temper mill is set to 0.8%-1.3%.

7. The method of claim 5, wherein, The roughness of the superfinishing roll of the 1# rack of the temper mill is set to 2.6μm-3.7μm.

8. The method of claim 1, wherein, The hot-rolling comprises reheating, finish rolling and coiling; The temperature of the reheating is 1170℃-1240℃. The temperature of the finish rolling is 850℃-890℃. The temperature of the coiling is 550℃-590℃.

9. The method of claim 1, wherein, The temperature of the batch annealing is 585℃-595℃.

10. The method of claim 1, wherein, The set chemical composition is C, Si, Mn, P, S, Als, N, the rest is Fe and inevitable impurities; wherein, C: 0.05wt%-0.07wt%; Si: ≤0.03wt%; Mn: 0.3wt%-0.4wt%; P: ≤0.015wt%; S: ≤0.015wt%; Als: 0.025wt%-0.055wt%; N: 0.003wt%-0.006wt%.

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