JP3449003B2 - Steel plate for cans and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate for a can, which is mainly used after being tin-plated (electrotin plating), particularly DI.
(Drawn and Wall Ironed) The present invention relates to a steel sheet suitable for use in a can and a manufacturing method thereof.

[0002]

2. Description of the Related Art Steel sheets for DI cans are required to be particularly soft, so that they have been conventionally manufactured mainly by using a low carbon steel as a raw material by a box annealing method. However, the box annealing method has a low production efficiency and has an essential problem that various surface defects are chronically generated. In order to solve these problems, various manufacturing methods by continuous annealing have been studied. However, a steel sheet manufactured by applying a continuous annealing method to a normal low carbon aluminum killed steel has a limit in softening the steel sheet, and it is also difficult to reduce the aging property. It is advantageous when "bottom pressure resistance" of the can is required, but in terms of continuous high-speed can manufacturing (hereinafter simply referred to as "high-speed continuous can manufacturing"). It was a disadvantage.

A proposal as a solution to this problem is disclosed in, for example, Japanese Unexamined Patent Publication No. 2-118027, in which ultra low carbon steel is used as a material.
Cold rolling, after the continuous sintering blunt, a method of enhancing the steel sheet to temper rolling at a reduction ratio range of 15% to 45% is disclosed.

[0004]

However, in the case of manufacturing by this method, although the high-speed continuous can-making property is improved to some extent, not only has it not yet reached a sufficient range, but also the bottom compressive strength is extremely lowered. Because of concern, it was necessary to devise the shape of the bottom of the can.

Therefore, an object of the present invention is to have sufficient bottom withstand pressure strength that can cope with gauge down, and
It is to propose a steel sheet having a high-speed continuous can-making property that has never been seen and a method for manufacturing the same. Further, an object of the present invention is to provide a steel sheet having a small workability, in particular, an in-plane anisotropy of r value (hereinafter abbreviated as “Δr”) and its production in addition to the above bottom pressure resistance and high-speed continuous can-making property. To propose a method.

[0006]

The inventors of the present invention have found that the above bottom pressure resistance and high-speed continuous can-making property, or further, Δ
Regarding the characteristics such as r, a detailed study was conducted focusing on the work hardening behavior of the material. As a result, the parts that require strength and the parts that require workability have different processing histories in the can making process. Therefore, each seemingly contradictory property is related to the composition of steel, especially the contents of C and Nb. By controlling appropriately and controlling the structure by optimizing each manufacturing condition such as hot rolling, cold rolling, and annealing, it was found that both are dramatically improved, and the present invention has been completed. It was.

That is, the gist of the present invention is as follows. (1) C: 0.0005 to 0.0030 wt%, Si: 0.20 wt% or less, Mn:
0.05 to 0.60 wt%, P: 0.100 wt% or less, S: 0.010
wt% or less, Al: 0.100 wt% or less, N: 0.0050 wt% or less, Nb: 0.003 to 0.020 wt%, including the above C and
Nb is contained in an atomic ratio of Nb / C: 0.70 to 1.70, the balance is Fe and inevitable impurities, and the average ferrite grain size is 15 μm or less. steel sheet.

(2) C: 0.0005 to 0.0030 wt%, Si: 0.20 wt
%, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less, S: 0.010 wt% or less, Al: 0.100 wt% or less,
N: 0.0050 wt% or less, Nb: 0.003 to 0.020 wt% included, Ni: 0.05 to 0.50 wt%, Cr: 0.05 to 0.50 wt%
And Cu: containing one or more selected from 0.05 to 0.50 wt%, and the above C and Nb are contained in an atomic ratio of Nb / C: 0.70 to 1.70. A steel sheet for a can, characterized in that the balance consists of Fe and unavoidable impurities, and has an average ferrite grain size of 15 μm or less.

(3) C: 0.0005 to 0.0030 wt%, Si: 0.20 wt
%, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less, S: 0.010 wt% or less, Al: 0.100 wt% or less,
N: 0.0050 wt% or less, Nb: 0.003 to 0.020 wt% are included, and the above C and Nb have an atomic ratio of Nb / C: 0.70 to 1.
After the steel slab containing 70% of the content and the balance of Fe and inevitable impurities is heated, it is subjected to hot rough rolling and (Ar ₃
After hot finish rolling in the temperature range of (transformation point −30 ° C.) to (Ar ₃ + 100 ° C.), and then water cooling is started within 0.5 sec after the finish rolling, and after cooling at a rate of 30 ° C./sec or more. , 680
It is wound up in the temperature range of ~ 580 ℃, pickled, and then 83
A method for manufacturing a steel sheet for cans, comprising cold rolling at a rolling reduction of not less than%, annealing at a recrystallization temperature to 800 ° C, and temper rolling at a rolling reduction of not more than 15%.

(4) C: 0.0005 to 0.0030 wt%, Si: 0.20 wt
%, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less, S: 0.010 wt% or less, Al: 0.100 wt% or less,
N: 0.0050 wt% or less, Nb: 0.003 to 0.020 wt% included, Ni: 0.05 to 0.50 wt%, Cr: 0.05 to 0.50 wt%
And Cu: containing one or more selected from 0.05 to 0.50 wt%, and the above C and Nb are contained in an atomic ratio of Nb / C: 0.70 to 1.70. After heating the steel slab, the balance of which is Fe and unavoidable impurities,
After hot rough rolling, (Ar ₃ transformation point −30 ° C.) to (Ar ₃ +100
Hot finish rolling in the temperature range of ℃), then start water cooling within 0.5 sec after the finish rolling, cool at a rate of 30 ℃ / sec or more, and wind in the temperature range of 680 to 580 ℃. After further pickling, cold rolling is performed at a reduction rate of 83% or more, then annealing is performed at a temperature range of recrystallization temperature to 800 ° C, and temper rolling is performed at a reduction rate of 15% or less. Of manufacturing steel sheet for cans.

[0011]

The function of each limitation in the present invention will be described below.
It will be described in order from the component composition. C: 0.0005 to 0.0030 wt% It is desirable to reduce the C content from the viewpoint of improving elongation and r-value, but if it is less than 0.0005 wt%, the surface after processing is roughened due to the remarkable coarsening of the grain size, a so-called orange peel phenomenon. There is a risk that it will become apparent and cause troubles with poor appearance. On the other hand, if it exceeds 0.0030 wt%, the r value tends to decrease and the deterioration of aging resistance becomes remarkable, which is advantageous for simply improving the bottom pressure resistance strength, but for high-speed continuous can-making property. It will be a disadvantage. Therefore, the content of C is 0.0005-
The amount is 0.0030 wt%, preferably 0.0005 to 0.0025 wt%.

Si: 0.20 wt% or less Si has a large strengthening ability and is expected to have a deoxidizing effect.
If it is contained in excess of wt%, the surface treatment property is significantly deteriorated, so the content is set to 0.20 wt% or less, more preferably 0.10 wt% or less.

Mn: 0.05 to 0.60 wt% Mn must be contained according to the amount of S inevitably mixed in, in order to prevent red hot embrittlement of the steel, and at least 0.05.
Red hot brittleness can be prevented by adding more than wt%. Also,
Mn lowers the Ar ₃ transformation point during hot rolling, is advantageous for relaxing restrictions on the hot rolling finish temperature, and has the effect of improving strength by solid solution strengthening. In addition, Mn is particularly effective in making the structure uniform and fine. However, the Mn content is 0.60
If it exceeds wt%, excessive hardening occurs and the r value deteriorates significantly. Therefore, the amount of Mn added is 0.05 to 0.60 wt%, preferably 0.10 to 0.50 wt%.

P: 0.100 wt% or less, P is an element effective for increasing strength because it has a large solid solution strengthening ability like Si, but a large amount of P deteriorates corrosion resistance and embrittles the material. In addition, it limits the recrystallization temperature to 0.100 wt% or less. Note that 0.02
It is preferably 0 wt% or less.

S: 0.010 wt% or less S content is a harmful element that increases inclusions in the steel and deteriorates workability. The amount of Mn added necessary for fixing is increased, and the regulation of hot rolling finish temperature is strengthened. 0.010 wt%
Hereafter, it is desirable that the content be 0.005 wt% or less.

Al: 0.100 wt% or less Al is an element added as a deoxidizing agent for steel. But,
If it is added in excess of 0.100 wt%, the surface properties will be deteriorated and the surface treatment will be impaired, so it is necessary to add it in the range of 0.100 wt% or less. Although there is no particular lower limit, an addition amount of 0.005 wt% or more is preferable in order to prevent inclusions from remaining in the steel. Further, 0.020 to 0.080 wt% is more preferable for making the structure finer and stabilizing N fixing.

N: 0.0050 wt% or less N is a harmful element that hinders workability, but an unnecessarily small amount causes an increase in steel melting cost. Since Al is added in the present invention, the upper limit of N can be up to 0.0050 wt%. Therefore, N is limited to 0.0050 wt% or less, but it is preferably 0.0050 wt% or less in consideration of the stability of operation.

Nb: 0.003 to 0.020 wt% Nb is an element effective in improving the in-plane anisotropy of the steel sheet and making the crystal grains finer, and the detailed mechanism is unknown, but D
It is also an element that reduces the load during I molding. In order to obtain such effects, it is necessary to add at least 0.003 wt% or more. However, if added over 0.020 wt%,
In addition to the saturation of these effects and higher costs,
The upper limit is set to 0.020 wt% because it will also increase the recrystallization temperature.

Nb / C: 0.70 to 1.70 Nb and C have an atomic ratio of Nb / C of 0.70 in addition to the above range.
Need to satisfy ~ 1.70. That is, Nb / C is 0.
If it is less than 70, the detailed mechanism is unclear, but the effect of reducing the load during DI molding is not observed, while if it exceeds 1.70, Δr increases and ears become large during deep drawing. Therefore, the atomic ratio Nb / C is in the range of 0.70 to 1.70, preferably 1.00 to 1.50.

In the present invention, it is possible to add at least one of Ni, Cr and Cu in the range of 0.05 to 0.50 wt% in addition to the above basic components. Ni: 0.05 to 0.50 wt%, Cr: 0.05 to 0.50 wt%, Cu: 0.05 to
0.50 wt%: Ni, Cr and Cu all have a grain refining function of the structure, lower the Ar ₃ transformation point during hot rolling, and are advantageous in relaxing restrictions on the hot rolling finishing temperature. Also,
Since these elements have a relatively small solid solution strengthening ability, they have little adverse effect of unnecessarily increasing the strength of the steel sheet and lowering the high-speed continuous can-making property.These effects are independent of single addition or composite addition, respectively. , 0.05 wt% or more, but even if added over 0.50 wt%, the effect is saturated and the cost is unnecessarily increased, so the content is limited to 0.50 wt% or less. Even if these elements are added alone, 2
Even if the elements or more are added together, the same effect is exhibited.

Ferrite average particle size: 15 μm or less If the ferrite average particle size is reduced, the reason is not clear, but during high-speed continuous can manufacturing, the load is not significantly increased and the bottom compressive strength is relatively large. It is possible to increase the strength of the portion that remains at a low processing rate. Such high-speed continuous can-making property becomes particularly remarkable when the as-annealed state exhibits an extremely low aging index. This effect is exhibited when the average ferrite grain size is 15 μm or less, preferably 12 μm or less, and it is desirable that the grain size control is uniform. The aging index (AI) at which the effect of the average ferrite grain size is remarkably obtained is 0.5 kgf when the AI value in the as-annealed state is 0.5 kgf.
/ mm ² or less, preferably 0.2 kgf / mm ² or less.

The steel sheet for a can according to the present invention can be obtained only by an optimized combination of the above chemical composition and manufacturing conditions. Next, the reasons for limiting the manufacturing method will be described.・ Hot finish rolling temperature: (Ar ₃ transformation point -30 ° C) ~ (Ar ₃ +10
(0 ° C) (Ar ₃ transformation point -30 ° C), the finally obtained structure becomes coarse, so that in addition to the decrease in strength, the resistance to roughening of the surface is decreased, and a so-called "ridging" phenomenon appears. The risk of causing a poor appearance increases. On the other hand, if the finish rolling temperature exceeds (Ar ₃ +100 ° C), the damage of the hot rolling roll will be large, which will not only be a major obstacle to the production, but also the surface properties of the steel sheet itself Become. Furthermore, the steel sheet structure tends to become coarse and the in-plane anisotropy tends to increase. Therefore, the hot finish rolling temperature is (Ar ₃ transformation point −30 in order to improve workability represented by r value.
℃)-(Ar ₃ +100 ℃) is necessary. In addition,
The preferred temperature range is (Ar ₃ transformation point -20 ° C) to (Ar ₃ + 50 ° C)
Is.

Start of water cooling: Within 0.5 sec after finishing rolling After finishing rolling, it is necessary to start cooling immediately in order to prevent coarsening of the structure of the steel sheet. Since Nb is added to the steel of the present invention, coarsening of the structure tends to be suppressed. However, if the elapsed time from the finish rolling to the start of water cooling exceeds 0.5 sec, the structure becomes coarse and the grains become conspicuous, which is not preferable. Even better results can be obtained by setting the elapsed time to 0.2 sec or less.

Cooling rate: 30 ° C./sec or more It is an important requirement to control the cooling rate along with the time until the above cooling starts. By setting the average cooling rate to about 30 ° C./sec or more, Finally, a cold rolled annealed plate having a uniform fine structure is obtained. The preferable cooling rate is
40 ℃ / sec or more. In the ultra-thin steel sheet targeted by the present invention, the thickness of the mother plate is thin and high-speed rolling is difficult, so the method of continuous rolling is effective.

Winding temperature: 680 to 580 ° C. Control of the winding temperature is also important for controlling the structure of the steel sheet. If the winding temperature exceeds 680 ° C, the final microstructure and uniformity of the steel sheet cannot be achieved. Also, it is presumed that if the temperature is lower than 580 ° C, the state of NbC deposition may change, but the aging index could not be reduced to 0.5 kgf / mm ² or less in the as-annealed state, and excellent high-speed continuous can manufacturing It becomes difficult to obtain sex. The desirable winding temperature range is 680 to 620 ° C from the viewpoint of improving the average r value.

Cold rolling reduction: 83% or more If the cold rolling reduction is less than 83%, good r value and Δr value cannot be obtained, so it is necessary to set it to 83% or more. The upper limit of the cold rolling reduction is not particularly required, but it is preferably 98% or less in order to avoid increase in the difficulty of operation.

Annealing temperature: recrystallization temperature to 800 ° C. The annealing temperature is required to be at least the recrystallization temperature or higher in order to improve the ductility of the steel sheet and the formability such as r value. This recrystallization temperature depends on the working heat history of the steel sheet, but is 720 to 750 ° C. in the component composition according to the present invention, and it is necessary to anneal at a temperature higher than this. On the other hand, if annealing is performed at a temperature higher than 800 ° C, the operation becomes difficult, and the structure becomes coarse, which improves the high-speed continuous can-making property. Degradation becomes remarkable.

· Rolling reduction of temper rolling: 15% or less The temper rolling after annealing is set according to the target strength of the can body and the yield stress of the raw material, but the temper rolling was performed beyond 15%. In this case, the yield stress of the material is remarkably increased, which not only increases the risk of causing a defective shape at the time of molding, but also leads to deterioration of Δr, which causes remarkable earing. From the viewpoint of the formability of the steel sheet, it is preferably 10% or less.

Since the effect of the present invention becomes more remarkable as the thickness of the steel sheet becomes thinner, it can be advantageously applied and the effect can be exhibited when the sheet thickness is 0.30 mm or less, preferably 0.240 mm or less. Further, the above steel sheet is used as it is or after being subjected to a surface treatment using this steel sheet as an original plate, to the can making process. As the surface treatment, usual electric tin plating, chrome plating and other plating treatments, and various coating treatments are advantageously suitable.

[0030]

【Example】

-Example 1 The slab obtained by smelting the steel of the composition of ingredients shown in Table 1 in the converter was reheated to 1250 ° C, and hot finish rolling was completed in the temperature range of 860-950 ° C. Here, the finish rolling temperature was controlled so as to fall within the range of (Ar ₃ transformation point −30 ° C.) to (Ar ₃ transformation point + 100 ° C.) according to each steel composition. After finishing rolling, cool at a rate of 35 ° C / sec within 0.5 sec,
It was wound at 620 ° C. Then, after pickling, reduction rate: 88%
Was cold-rolled into a 0.23 mm cold-rolled steel sheet. Each of these cold-rolled steel sheets was annealed in a continuous annealing furnace at 760 ° C x 20 sec, cooled to 350 ° C at a cooling rate of 25 ° C / sec, and temper-rolled at a rolling reduction of 1 to 3%. . After that, # 25 tin plating treatment was continuously performed on a halogen type electric tin plating line to obtain a tin plate.

[0031]

[Table 1]

Table 2 shows the average grain size of ferrite, the AI after annealing and before temper rolling of cold-rolled steel sheets (original plating sheets).
(Aging index) is measured and the results of investigation of tensile properties are shown. The average ferrite grain size is JIS G05.
The measurement was carried out according to the method specified in 52. Also, the tensile properties are J
In the test using the IS5 tensile test piece, AI (aging index) was 100 ° C after the steel sheet was prestrained with 7.5% of prestrain.
The aging treatment was performed for 30 minutes, and the change in deformation stress before and after aging was evaluated.

[0033]

[Table 2]

Next, each plated plate was made into a 350 ml can, and after baking treatment, the bottom pressure resistance was investigated.
The cans used at that time were the latest high-speed can-making machines (maximum can-making speed: 5
00 cans / min) at a speed of 350 cans / min and continuous 50
High-speed continuous can-making properties were evaluated by making 0 or more cans.
Here, the bottom compressive strength was evaluated by applying a hydrostatic pressure to the inside of the can and evaluating the limit pressure at which the bottom buckles. The evaluation items for high-speed continuous can manufacturing are 1) molding load, 2) can surface properties, 3)
It is removable. The molding load is a load detector that is attached to the can making machine to detect the molding load required for can making.This molding load corresponds to obstacles in actual machine production, such as die wear, and its value is The smaller the material, the better. The property of the can surface is a surface condition caused by partial melting of Sn on the tinned surface due to heat generated during molding, and if this is inferior, so-called poor appearance will result. Detachability is DI
It is the characteristic when pulling out the processed can from the punch,
Poor detachability causes problems such as crushing the can edge with a so-called "stripper ring". Table 2 also shows the results of an investigation on the bottom pressure resistance and the high-speed continuous can-making property of the thus obtained can.

From the results shown in Table 2, when the steel sheet was produced according to the method of the present invention, the sacrifice of other properties was achieved without sacrificing other properties.
It can be seen that sufficiently high bottom pressure resistance and high-speed continuous can-making property are obtained. Observation of the obtained can also confirmed that the can obtained according to the present invention had good surface properties and corrosion resistance, and also had good cold rolling property in the intermediate step.

Example 2 A slab obtained by melting steel (Ar ₃ : 870 ° C.) having the composition shown in Table 3 in a converter is reheated to 1250 ° C. to 1340 ° C. 0.210 mm in the same manner as in Example 1 except for the conditions.
Cold-rolled steel sheet and tin-plated steel sheet were manufactured. Here, the recrystallization temperature of the cold-rolled sheet was about 750 ° C.

[0037]

[Table 3]

[0038]

[Table 4]

Table 5 shows the results of measuring the average grain size of ferrite, the results of measuring the AI (aging index) after annealing and before temper rolling, and the r value, for the cold-rolled steel sheet (plating original sheet) in the same manner as in Example 1. The result of investigating Δr is shown. Where r-value,
The Δr value was obtained by taking JIS No. 5 tensile test pieces from the rolling direction of the steel sheet, the direction of 45 ° with respect to the rolling direction, and the directions of 90 ° with respect to the rolling direction. The Rankford value in each direction was measured from the ratio of the strain in the width direction and the strain in the plate thickness when tensile prestrain was applied, and the value was obtained by the following formula. r = (r _L + 2r _D + r _T ) / 4 Δr = (r _L −2r _D + r _T ) / 2 where r _L , r _D, and r _T are the rolling directions,
It represents the Rankford value in the direction of 45 ° to the rolling direction and 90 ° to the rolling direction. If the uniform elongation of the steel sheet is too small to measure by the above method, JISG31
35 was determined by the natural vibration method.

[0040]

[Table 5]

Next, each plated plate was made into a 350 ml can,
The bottom pressure resistance was investigated after the paint baking process was performed. For the can making at that time, using the latest high-speed can making machine (maximum can making speed: 500 cans / min), at a speed of 400 cans / min, 500 or more cans can be continuously produced, thereby achieving high-speed continuous canning property. Was evaluated. The bottom pressure resistance and the high-speed continuous can-making property were evaluated in the same manner as in Example 1. Table 5 also shows the results of the investigation on the bottom pressure resistance and the high-speed continuous can-making property of the thus obtained cans.

From the results shown in Table 5, when the steel sheet was manufactured according to the present invention, sufficiently high bottom pressure resistance and excellent high-speed continuous can-making property were obtained without sacrificing other properties, and It can be seen that the r value and Δr are also excellent. Observation of the obtained can also confirmed that the can obtained according to the present invention had good surface properties and corrosion resistance, and also had good cold rolling property in the intermediate step.

[0043]

According to the present invention, excellent high-speed continuous can-making property and high bottom pressure resistance can be achieved. Further, according to the present invention, since excellent characteristics of r value and Δr can be obtained, molding at the time of can molding is easy, and earrings are less likely to occur.
Therefore, according to the present invention, stable bottom pressure strength and stable can body strength can be obtained, the thickness of the can manufacturing base plate can be reduced, and the energy required for can manufacturing can be saved. Industrially significant effects can be enjoyed, such as the high yield of cans.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Satoru Sato 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Works (72) Hideo Kuminato 1 Kawasaki-cho, Chuo-ku, Chiba, Kawasaki Chiba Steel Works, Ltd. (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 38/00-38/60 C21D 9/46-9/48

Claims (4)

(57) [Claims] 1. C: 0.0005 to 0.0030 wt%, Si: 0.20 wt% or less, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less,
S: 0.010 wt% or less, Al: 0.100 wt% or less, N: 0.
0050 wt% or less, Nb: 0.003 to 0.020 wt%, the above C and Nb are contained in the atomic ratio of Nb / C: 0.70 to 1.70, and the balance is Fe and inevitable impurities. Moreover, a steel sheet for cans having an average ferrite grain size of 15 μm or less. 2. C: 0.0005 to 0.0030 wt%, Si: 0.20 wt% or less, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less,
S: 0.010 wt% or less, Al: 0.100 wt% or less, N: 0.
0050 wt% or less, Nb: 0.003 to 0.020 wt% and Ni: 0.05 to 0.50 wt%, Cr: 0.05 to 0.50 wt% and
Cu: Includes one or more selected from 0.05 to 0.50 wt%, and the above C and Nb are in atomic ratio.
Nb / C: A steel sheet for cans, which is contained by satisfying the relationship of 0.70 to 1.70, the balance being Fe and inevitable impurities, and having an average ferrite grain size of 15 μm or less. 3. C: 0.0005 to 0.0030 wt%, Si: 0.20 wt% or less, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less,
S: 0.010 wt% or less, Al: 0.100 wt% or less, N: 0.
0050 wt% or less, Nb: 0.003 to 0.020 wt%, the above C and Nb are contained in the atomic ratio of Nb / C: 0.70 to 1.70, and the balance is Fe and inevitable impurities. After heating the slab, hot rough rolling is performed, and hot finish rolling is performed in the temperature range of (Ar ₃ transformation point −30 ° C.) to (Ar ₃ + 100 ° C.), followed by water cooling within 0.5 sec after the finish rolling. 680 to 580 after cooling at a rate of 30 ° C / sec or more
Winding in the temperature range of ℃, further pickling, cold rolling at a reduction rate of 83% or more, then recrystallization temperature ~ 800
A method for producing a steel sheet for cans, comprising annealing in a temperature range of ℃, and temper rolling at a rolling reduction of 15% or less. 4. C: 0.0005 to 0.0030 wt%, Si: 0.20 wt% or less, Mn: 0.05 to 0.60 wt%, P: 0.100 wt% or less,
S: 0.010 wt% or less, Al: 0.100 wt% or less, N: 0.
0050 wt% or less, Nb: 0.003 to 0.020 wt% and Ni: 0.05 to 0.50 wt%, Cr: 0.05 to 0.50 wt% and
Cu: Includes one or more selected from 0.05 to 0.50 wt%, and the above C and Nb are in atomic ratio.
After heating a steel slab containing Nb / C: 0.70 to 1.70 with the balance being Fe and unavoidable impurities, after hot rough rolling, (Ar ₃ transformation point −30 ° C.) to (Ar Hot rolling in the temperature range of ₃ + 100 ℃), and then after the finish rolling
Start water cooling within 0.5 sec, cool at a rate of 30 ° C / sec or more, wind in the temperature range of 680 to 580 ° C, further pickle and cold-roll at a reduction rate of 83% or more. Then, a method for producing a steel sheet for a can, which comprises annealing at a recrystallization temperature to 800 ° C. and temper rolling at a rolling reduction of 15% or less.