JPH09241744A - Production of steel sheet for can by annealing obviated process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology for producing a steel sheet for a can excellent in workability such as ridging resistance and stretch-flanging properties and furthermore excellent in material uniformity by a low-cost producing process in which annealing is not executed and the number of steps in the process is reduced. SOLUTION: A steel slab having a compsn. contg., by weight, <=0.01% C, <=0.02% Si, 0.05 to 0.5% Mn, <=0.02% P, <=0.02% S, <=0.1% solAl and <=0.0030% N, contg., at need, one or two kinds of 0.002 to 0.02% Nb and 0.001 to 0.02% Ti, and the balance Fe with inevitable impurities is subjected to rough rolling, and the obtd. sheet bar is joined with the preceding sheet bar. Next, it is subjected to finish rolling so as to regulate the finishing temp. to the Ar3 -50 deg.C or above and is coiled in the temp. range of 600 to 750 deg.C, and after the removal of scales, cold rolling is executed at a draft of 40 to 90%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process-saving method of manufacturing a steel sheet for cans in which annealing after cold rolling is omitted.
In particular, the present invention relates to a method of producing a steel sheet for cans, which is excellent in workability such as ridging resistance and stretch flangeability and is also excellent in material uniformity, and which is suitable for use as an ultrathin tin plate or tin-free steel.

[0002]

2. Description of the Related Art Beverage cans and container cans such as 18 liter cans and pail cans are roughly classified into two-piece cans and three-piece cans according to their manufacturing process. Two-piece cans are made of surface-treated steel sheet that has been subjected to tin plating, chrome plating, chemical conversion treatment, oil coating, etc., shallow drawing, DWI (Drawn and Wall Ironing).
d) It is a two-part can in which the can bottom and the can body are integrally formed by processing such as processing and DRD (Drawn and Redrawn) processing, and a lid is attached to this. A three-piece can is a three-part can in which a surface-treated steel plate is bent into a cylindrical shape or a rectangular tube shape, the ends are joined to form a can body, and then a canopy and a bottom lid are attached to the can body. is there.

Since the cost of the can thus produced is high in the material cost, the demand for cost reduction of the steel sheet is strong. A promising method to respond to this is to replace continuous box annealing with continuous annealing, which has high production efficiency and excellent yield and surface quality. For example, Japanese Patent Publication No. 63-1
It was a technique like Japanese Patent No. 0213. In addition, in addition to this, a manufacturing technology for a soft steel sheet for cans of about T2 (50-56) with a tempering degree expressed by the value of Rockwell hardness (HR30T) has been developed. Furthermore, a technique for producing a soft steel sheet by continuous annealing has been developed, and for example, Japanese Patent Publication No. 1-52
As disclosed in Japanese Patent No. 452, a technique has been proposed in which ultra-low carbon steel is applied as a raw material, and steel plates for cans having various hardnesses are prepared by combining work hardening after annealing.

There is a demand for further cost reduction in this kind of steel sheet for cans, and in order to meet this demand, efforts have been made toward the development of new manufacturing techniques. As one method of cost reduction, there is a movement to reduce the plate thickness of the steel plate used and to strengthen the diameter reduction (neck-in) forming of the upper lid. The materials applied to these methods are required to have more severe properties, and it has been impossible to produce a steel sheet for cans having good workability by a method other than the above-mentioned conventional processes. As another technique aiming at further cost reduction, Japanese Patent Laid-Open No. 280926/1992 discloses that ultra-low carbon steel is used as a raw material for finish hot rolling in the α region, followed by self-annealing to grow crystal grains, and thereafter. A manufacturing method by a process-saving process in which subsequent annealing and temper rolling are omitted by performing cold rolling is disclosed.

[0005]

However, the steel sheet produced by this method suffers from ridging peculiar to α-region hot rolling (streak defects that occur during processing) and its stretch flangeability is not very good. There was a problem. Therefore, an object of the present invention is to solve the problems that the above-mentioned conventional techniques have, to perform canning excellent in workability such as ridging resistance and stretch flangeability in a low-cost manufacturing process that does not perform annealing and that saves a process. The purpose is to propose a technology for manufacturing steel sheets for use. Another object of the present invention is to propose a technique for stably producing a steel sheet for cans having excellent material uniformity in this process-saving process.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present inventors first examined the properties required for a steel sheet for cans and concluded as follows. 1) Unlike deep drawing steel sheets used in automobiles and the like, a high r value is not an essential condition. 2) It is desirable that the in-plane anisotropy (Δr) of the r value is small. 3) It is desirable that non-uniformity of deformation such as ridging does not occur. 4) A fine structure is desirable in terms of uniform deformation. 5) The manufactured steel sheet does not necessarily have to be completely non-aged like a box annealed material (low carbon aluminum killed steel),
It is desirable not to age the normal continuous annealed material (low carbon aluminum killed steel) because it causes problems in the can making process and subsequent secondary and tertiary processes. 6) It is desirable to have local ductility at a strain rate that is one to two orders of magnitude faster than those, as opposed to the ductility obtained by a normal tensile test. The present invention was conceived by conducting metallurgical studies such as steel composition and manufacturing conditions that govern the above properties as a steel sheet for cans. That is, the gist configuration of the present invention is as follows.

(1) C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02
A steel slab having a composition of wt% or less, sol Al: 0.1 wt% or less, N: 0.0030 wt% or less, and the balance of Fe and unavoidable impurities is roughly rolled, and the obtained sheet bar precedes the sheet bar. Then, finish rolling is performed so that the end temperature becomes Ar ₃ −50 ° C. or higher, the coil is wound in the temperature range of 640 to 750 ° C., the scale is removed, and cold rolling is performed at a reduction rate of 40 to 90%. A method of manufacturing a steel sheet for cans by the step of omitting annealing, the method comprising:

(2) C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02
A steel slab having a composition of wt% or less, sol Al: 0.1 wt% or less, N: 0.0030 wt% or less, and the balance of Fe and unavoidable impurities is roughly rolled, and the obtained sheet bar precedes the sheet bar. And then finish rolling under lubrication so that the end temperature is less than Ar ₃ −50 ° C.
A method for producing a steel sheet for a can by a step of omitting annealing, characterized in that the steel sheet is rolled and self-annealed in a temperature range of 50 ° C, the scale is removed, and then cold rolling is performed at a reduction rate of 40 to 90%.

(3) C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02
wt% or less, sol Al: 0.1 wt% or less, N: 0.0030 wt% or less, and Nb: 0.002 to 0.02 wt%, Ti: 0.001 to 0.
A steel slab containing 02 wt% of 1 or 2 and the balance of Fe and inevitable impurities is roughly rolled, the obtained sheet bar is joined to the preceding sheet bar, and then the finish temperature is Ar ₃ Finishing rolling is performed at -50 ° C or higher, winding is performed in the temperature range of 640 to 750 ° C, scale removal, and then cold rolling is performed at a reduction rate of 40 to 90%. For manufacturing steel sheet for cans.

(4) C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02
wt% or less, sol Al: 0.1 wt% or less, N: 0.0030 wt% or less, and Nb: 0.002 to 0.02 wt%, Ti: 0.001 to 0.
A steel slab containing 02 wt% of 1 or 2 and the balance of Fe and inevitable impurities is roughly rolled, the obtained sheet bar is joined to the preceding sheet bar, and then the finish temperature is Ar ₃ Finish rolling under lubrication so that the temperature is less than -50 ° C, wind and self-anneal in the temperature range of 600 to 750 ° C, remove the scale, and perform cold rolling at a reduction rate of 40 to 90%. A method for manufacturing a steel sheet for cans by the step of omitting annealing.

(5) The finishing rolling speed is 1000 m / min or more at the exit speed of the final stage, and the speed fluctuation amount is 1
The method for producing a steel sheet for cans according to any one of (1) to (4) above, which is 0% or less.

(6) A method of manufacturing a steel sheet for a can, which is cold-rolled according to any one of the above (1) to (5) and then subjected to heat-holding heat treatment at 200 to 400 ° C. for 5 seconds or more.

(7) After cold rolling according to the method described in any one of (1) to (5), surface treatment is performed, and then 20
A method for producing a steel sheet for cans, which comprises heat-holding heat treatment for 5 seconds or more at 0 to 400 ° C.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In order to improve the r value, it is necessary to carry out recrystallization annealing after cold rolling. However, if a relatively large r value is not required, the recrystallization annealing step can be omitted. It is possible. However, in a conventional cold-rolled steel sheet in which the recrystallization annealing step is simply omitted and the cold rolling → annealing → secondary rolling step is performed, ductility and stretch flangeability are insufficient as a steel sheet for a can. It was not possible to satisfy the requirement for the application where the drawability is required. Further, in order to suppress ridging and improve stretch flangeability, the purpose cannot be achieved by simply recrystallizing crystal grains as large as possible, as aimed at in Japanese Patent Application Laid-Open No. 4-280926.

Therefore, as a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have used steel having an appropriately controlled composition and optimized the thermo-mechanical treatment conditions in the hot rolling process to reduce the cold rolling after the cold rolling. It has been found that it is possible to omit the annealing step, and it is effective to avoid the mixed grains and to recrystallize uniformly even if the steel has a slightly fine grain structure. Then, in order to obtain recrystallized grains that satisfy such conditions,
It has been found that it is extremely effective to carry out so-called "endless rolling" in which the sheet bar is joined to the preceding sheet bar in the hot rolling step and finish rolling is performed in an endless state. Moreover, it was also found that this endless rolling improves the uniformity of the material in the coil. This is because in the case of steel sheets for cans, it is difficult to maintain the finishing temperature and winding temperature evenly throughout the coil due to the thin thickness of the hot-rolled sheet. This means that it is possible to solve at once a problem that has been a bottleneck in the production of steel sheets for cans, such as the inability to crystallize the whole coil, and the role of endless rolling is great.

The reasons why the steel composition and manufacturing conditions are limited in the above-mentioned constitution in the present invention will be explained below. C: 0.01 wt% When the content of C exceeds 0.01%, the amount of residual solid solution carbon increases, so that sufficient local ductility necessary for can forming cannot be obtained. However, it is not preferable because cracking occurs at the time of forming the stretch flange of the winding-fastened portion, which is the final step of can making. Further, when the carbon content is larger than this, the work hardening amount becomes large, the material becomes high in strength, which causes wrinkles during the mouth-drawing process and causes a problem during welding. Further, it is necessary to limit the amount of C also in terms of aging deterioration. Incidentally, in order to obtain a steel sheet having particularly excellent formability, it is desirable that the C content be 0.0030 wt% or less.

Si: 0.02 wt% Si is an element that deteriorates the surface properties of the steel sheet, and if the addition amount is too large, it is not desirable as a surface-treated steel sheet. Moreover, it hardens the steel, complicates the hot rolling process, and hardens the steel as a final product, which is not desirable. For the above reasons, the Si content is 0.02 wt% or less. Especially for applications where surface properties are strictly required, it is desirable to set it to 0.010% or less.

Mn: 0.05 to 0.50 wt% Mn is an element useful for preventing surface cracks and the like caused by hot embrittlement due to S, and at least 0.05 wt% is necessary to obtain the effect. is there. On the other hand, 0.50wt%
If added over, the transformation point becomes too low and hardens,
It adversely affects the subsequent cold workability and hardens the product plate. Therefore, the Mn content is 0.05 ~ 0.50wt%
And In order to obtain a soft steel sheet for cans, 0.20%
It is preferable to set the following.

P: 0.02 wt% or less P is an element harmful to the corrosion resistance, and the corrosion resistance is improved by reducing the content, but excessive reduction leads to an increase in manufacturing cost. From these tradeoffs, P
The content was 0.02 wt% or less. In addition, in order to remarkably improve the workability, it is preferably 0.010 wt% or less.

S: 0.02 wt% or less S increases the amount of inclusions such as MnS as the amount of S increases,
By reducing or reducing the local ductility represented by stretch-flangeability, the total elongation is significantly improved. Therefore, the S content must be limited to 0.02 wt% or less.
In order to remarkably improve the workability, it is preferable that the amount is 0.006 wt% or less and the Mn / S is 10 or more.

Sol Al: 0.10 wt% or less sol Al is an element necessary for deoxidation, but if it exceeds 0.10 wt%, not only the deoxidizing effect is saturated, but also inclusions increase,
It has a bad influence on moldability. Therefore, the content of sol Al is 0.
10 wt% or less. In order to secure stable manufacturing conditions, it is preferable to set it in the range of 0.020 to 0.040 wt%.

N: 0.0030 wt% or less N is an impurity element that is inevitably mixed in the steel and forms a precipitate to reduce elongation. Further, when N remains in a solid solution state, the steel is hardened. The strength of the steel sheet according to the method of the present invention is sufficient, and rather a softer one is desired. Therefore, the upper limit of N content is 0.0030wt.
%. From the viewpoint of workability, it is preferably 0.0020 wt% or less.

In addition to the above basic components, one or two kinds of Nb and Ti may be added to soften the steel. Nb: 0.002 to 0.02 wt%, Ti: 0.001 to 0.02 wt% Nb and Ti are elements useful for reducing aging and softening the steel due to carbon sticking. In order to obtain these effects, the contents of Nb and Ti should be at least respectively.
0.002 wt% and 0.001 wt% are required. On the other hand, if any element is added in excess of 0.020 wt%, the homogeneity of the recrystallized grains of the hot-rolled sheet is impaired, and not only a non-uniform structure is formed, but also the load during hot rolling is increased. For this reason,
The contents of Nb and Ti are 0.002-0.02wt% and
0.001 to 0.02 wt% When the workability is important, it is desirable that the range is 0.005 to 0.015 wt% in all cases.

Next, the manufacturing conditions will be described, including the reasons for limitation. (1) Hot rolling Slab heating temperature: If the slab heating temperature is too high, fine precipitates will be deposited during hot rolling, and the pinning effect by this will reduce the grain size of the hot rolled sheet. As a result, the hot-rolled sheet is likely to harden and the local deformability is reduced, which is not preferable. Therefore, it is desirable that the slab heating temperature is set to 1250 ° C. or lower to coarsen the precipitates and achieve both moldability and softening. It is preferably 1100 ° C or lower, and when heating the slab
It is better to deposit precipitates such as MnS coarsely and to make the grain size after hot rolling relatively large.

Endless rolling: Endless rolling is a particularly important constituent element in the method of the present invention. In the conventional rolling method for thin steel sheets, there is flapping at the coil tip until the start of winding and there is uneven cooling conditions, so it is not possible to increase the line speed. When it became able to be applied, it increased the speed and improved the productivity. In such a conventional method, it is inevitable that the rolling conditions, particularly the rolling speed, greatly vary not only in the front and rear ends of the coil but also in the longitudinal direction of the coil.

This phenomenon is extremely disadvantageous for improving the workability in the annealing omitting process, which is the object of the present invention, and in order to solve it, it is important to control the rolling speed within a certain range. Specifically, the exit speed of finish rolling is 1000 m / min or more, more preferably 1200 m / min.
Above, it is desirable that the amount of speed fluctuation in the coil is 10% or less, more preferably 5% or less. By performing finish rolling under these conditions, stable workability can be obtained.
Further, since this rolling speed is affected by the Nb amount, the reduction amount, the cooling conditions, etc., it may be controlled by taking these operating factors into consideration within the appropriate range.

Further, as in the case of steel plate for can, the uniformity of the material is
When required in the coil longitudinal direction, in the normal hot rolling method, there are many parts that are out of the hot rolling conditions (finishing temperature, cooling cycle) at the leading end and the trailing end of the coil, and the yield increases. descend. In particular, since the composition having the composition targeted by the method of the present invention has a relatively high transformation point, the coil tip and the trailing end are likely to be finished at a transformation point (below -50 ° C) or lower, resulting in residual or abnormal processing structure. Grains are likely to be generated, and when the rolling is completed in a relatively low temperature range below the Ar ₃ transformation point, it becomes difficult to recrystallize the entire coil by the self-annealing effect. In order to eliminate such a disadvantage, it is essential to perform endless rolling. For the reasons described above, it is important to perform endless rolling in order to make the material uniform.

Finishing temperature: The finishing temperature of hot rolling (finishing rolling finishing temperature) is (Ar ₃ transformation point −50 ° C.) or more, preferably Ar ₃ transformation in order to make the structure and grain size of the hot rolled sheet uniform. It should be above the point. By making the finishing temperature higher than the transformation point, further homogenization of the structure can be expected, but considering the influence of the processed structure and its fraction,
An Ar ₃ transformation point of up to -50 ° C is acceptable. When hot rolling is performed at a temperature lower than the Ar ₃ transformation point (Ar ₃ transformation point −50 ° C.) for cost reduction, rolling under lubrication, so-called warm lubrication rolling is performed. You can also In this case, it is important to perform sufficient recrystallization (self-annealing) after winding in order to obtain workability. For that purpose, the final pass is strongly pressed down, specifically, 20% in the final pass. It is desirable to carry out the above strong reduction. In any case, if a coarse structure remains due to finishing below the transformation point, 1) ridging occurs, and 2) after cold rolling, the hardness of the material in the plate thickness direction becomes non-uniform and Since it also causes a flange crack, it is necessary to avoid the formation of such a structure.
Therefore, when performing warm rolling, it is essential to perform endless rolling while ensuring uniform rolling by applying lubrication such as oil lubrication. The lower limit temperature of warm rolling is not particularly limited as long as the coiling temperature described later can be secured.

The winding temperature: coiling temperature (when performing hot rolled at Ar ₃ below transformation point -50 ° C.) recrystallization by self annealing effect and it is desirable high to encourage particle growth, Ar ₃
When hot rolling is performed at a transformation point of -50 ° C or higher, a temperature of 640 ° C or higher is required, and when hot rolling is performed at an Ar ₃ transformation point of lower than -50 ° C, a temperature of 600 ° C or higher is required. However, when the temperature exceeds 750 ° C, the scale thickness remarkably increases, and the descaling property during pickling deteriorates. In addition, it is difficult to wind up above 750 ° C from the actual operation. Therefore, the winding temperature is (Ar ₃ transformation point-
When performing hot rolling at 50 ° C or higher, the temperature should be 640 to 750 ° C.
When hot rolling is carried out below (Ar ₃ transformation point −50 ° C.), 600-
750 ℃.

(2) Cold rolling Cold rolling after pickling must be carried out at a reduction rate of 40 to 90%. Since the grain size of the hot rolled mother plate in the method of the present invention is relatively large, there is a possibility that the material will become non-uniform unless cold rolling is performed at a reduction ratio of 40% or more. The upper limit is 90% from the viewpoint of local ductility because the strength is sufficient considering the application. However, considering further the moldability, it is desirable to be 80% or less.

(3) Heat treatment after cold rolling In the method of the present invention, the steel sheet after cold rolling is subjected to heat treatment in a low temperature range, whereby softening and an increase in local deformability can be achieved. Molding such as flange molding becomes easier in the can manufacturing process. In this case, as the heat treatment conditions, it is desirable that the temperature is 200 ° C. or higher and the time is 5 seconds or longer. If the heat treatment temperature or time is less than this, the strain accumulated by cold rolling will not be recovered and softening will not occur. Moreover, carbon and nitrogen remaining in the steel may rather cause hardening, which is not preferable. Further, if the heating temperature exceeds 400 ° C, there is a risk of excessive softening due to recrystallization, etc., and there is also a concern that the temper color of the steel sheet surface or alteration such as plating will occur, so the upper limit of the heating temperature is set.
Set to 400 ° C. Here, the holding time is preferably 10 seconds to 30 minutes. In the normal can making process, steel plate,
A steel plate which has been subjected to surface treatment (tin plating, chromate treatment, etc.) as necessary is subjected to coating baking or film laminating treatment in a can manufacturing line, and then can manufacturing. During painting baking or film laminating process,
Since the steel sheet is heated to a temperature of 0 ° C. or higher for 5 seconds or longer, this step can also be used as the above low temperature heating step.

[0032]

EXAMPLE Steels having the chemical composition shown in Table 1 were melted, and subjected to rough rolling, finish rolling (endless rolling or normal rolling for comparison), winding, and pickling under the conditions shown in Table 2. After that, cold rolling was carried out at the reduction ratio shown in the table, and further, a part of them was heat-treated by heating to 210 ° C. and holding for 20 minutes. The tensile properties, Rockwell hardness and flange formability of the obtained test materials were investigated. here,
The tensile test was performed using JIS No. 5 test piece, and the Rockwell hardness scale was HR30T. Flange formability is that, under normal conditions, # 25 equivalent tin plating is performed, then roll forming and high speed seam welding are used to form a can body of a three-piece can, which is stretch flanged to cause cracking. The judgment was made based on the presence or absence of. Further, a sample was extracted from the total length of the coil, the formability in each part was evaluated, and the yield was calculated from the defective rate. Table 2 shows the results together. Further, using the steel A in Table 1, endless hot rolling was performed at a temperature below the transformation point, and at that time, the lubricating conditions and the reduction ratio of the final pass in finish rolling were variously changed.
This material was cold-rolled at a cold rolling reduction of 70%, and some were heat-treated by heating to 210 ° C and holding for 20 minutes. The same test was performed on the obtained test material. The results are shown in Table 3 together with the production conditions.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

It can be seen from Tables 2 and 3 that by performing hot finish rolling by endless rolling according to the method of the present invention and winding at a predetermined temperature, a soft steel sheet having high local rolling performance can be obtained. Further, in the case of warm rolling, it can be seen that particularly strongly reducing the final pass of finish rolling is effective for self-recrystallization of the hot rolled sheet. These steel sheet microstructures are the same as those annealed in the conventional process, and even if the annealing process is omitted, it is possible to obtain formability almost equivalent to that produced by the process including the conventional annealing process. It was also confirmed from the top of the metallographic structure. In addition, No. 2 to 4 of Table 3
Insufficient self-recrystallization caused the flange formability to deteriorate.

[0037]

As described above, according to the method of the present invention,
It is possible to manufacture a steel sheet for a can having excellent workability such as ridging resistance and stretch flangeability by a low-cost manufacturing process that does not perform annealing. Further, according to the method of the present invention,
In this process-saving process, the material uniformity is improved and the yield is improved, so that it is possible to manufacture a can steel plate with stable quality at a further lower cost.

Claims (7)

[Claims] 1. C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less, N : A steel slab containing 0.0030 wt% or less and the balance Fe and unavoidable impurities is roughly rolled, the obtained sheet bar is joined to the preceding sheet bar, and then the finishing temperature is Ar ₃ −50 ° C. As mentioned above, finish rolling is carried out, coiling is carried out in the temperature range of 640 to 750 ° C, scale is removed, and cold rolling is carried out at a rolling reduction of 40 to 90%. Steel plate manufacturing method. 2. C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less, N : A steel slab containing 0.0030 wt% or less and the balance Fe and unavoidable impurities is roughly rolled, the obtained sheet bar is joined to the preceding sheet bar, and then the finishing temperature is Ar ₃ −50 ° C. Finish rolling under lubrication to 600-75
A method for producing a steel sheet for cans by an annealing omission step, which comprises winding in a temperature range of 0 ° C, self-annealing, removing scale, and then cold rolling at a reduction rate of 40 to 90%. 3. C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less, N : 0.0030 wt% or less, Nb: 0.002 to 0.02 wt%, Ti: 0.001 to 0.02 wt%, 1 or 2 types, with the balance being Fe and unavoidable impurities. Then, the obtained sheet bar is joined to the preceding sheet bar, and then finish rolling is performed so that the end temperature becomes Ar ₃ −50 ° C. or higher.
Wind up in the temperature range of 0 to 750 ℃, remove the scale, and then 40
A method for manufacturing a steel sheet for cans by an annealing skip process, which comprises performing cold rolling at a reduction rate of 90%. 4. C: 0.01 wt% or less, Si: 0.02 wt% or less, Mn: 0.05 to 0.5 wt%, P: 0.02 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less, N : 0.0030 wt% or less, Nb: 0.002 to 0.02 wt%, Ti: 0.001 to 0.02 wt%, 1 or 2 types, with the balance being Fe and unavoidable impurities. and the resultant bonded sheet bar the preceding sheet bar and then to termination temperature is Ar ₃ below -50 ° C., under lubrication performs finish rolling, coiling at a temperature range of 600 to 750 ° C. A method for producing a steel sheet for a can by a step of omitting annealing, which comprises performing self-annealing, removing the scale, and then cold rolling at a reduction rate of 40 to 90%. 5. The finish rolling speed is 1000 m / min or more at the exit speed of the final stage, and the speed fluctuation amount is 10%.
It is the following, The manufacturing method of the steel plate for cans of any one of Claims 1-4. 6. A method for producing a steel sheet for a can, which is cold-rolled according to any one of claims 1 to 5 and then subjected to heat-holding heat treatment at 200 to 400 ° C. for 5 seconds or more. 7. After cold rolling according to the method of any one of claims 1 to 5, surface treatment is performed, and then 200 to
A method for manufacturing a steel sheet for a can, which is heat-treated at 400 ° C for 5 seconds or more.