JP3852210B2 - Steel plate for modified 3-piece can and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a steel plate for cans and a method for producing the same, and more particularly to a special three-piece can (such as a barrel shape) which is deformed three-dimensionally, such as a barrel shape, after forming the steel plate into a cylindrical shape and further imparting elongation strain in the circumferential direction. The present invention relates to a steel plate for cans suitable for use in a modified 3-piece can) and a method for producing the same.
[0002]
[Prior art]
The can container can be roughly classified into a two-piece can composed of a can body and an upper lid, and a three-piece can composed of a can body, an upper cover, and a bottom cover.
The manufacturing process of a three-piece can is relatively simple compared to that of a two-piece can and usually does not require particularly severe processing. In the three-piece can, after the steel plate is formed into a cylindrical shape, the top lid and the bottom lid are assembled in the final winding and tightening process on the can body joined by a method such as resin bonding, welding or soldering. Flange molding to prepare for the process was only a bottleneck in quality. The flange forming process in the winding process is a process of forming flange portions extending outward in the diameter direction at both ends of the can body so as to cover the can body, and the flange portion is cracked during the processing. May occur. If the flange cracks, the can contents will leak.
[0003]
However, in the conventional three-piece can, it can be said that this problem has been substantially solved by optimizing the steel composition and the secondary cold rolling reduction after annealing (see Japanese Patent Application Laid-Open No. 9-118928).
[0004]
[Problems to be solved by the invention]
However, in recent years, from the viewpoint of improving the design of the can, there has been an increasing demand for a three-piece can (hereinafter referred to as a deformed three-piece can) having a more three-dimensionally deformed shape than a simple cylindrical can. This situation is introduced, for example, in the magazine “THE CANMAKER” Feb. 1996, p32-37.
[0005]
These deformed three-piece cans are formed by joining steel plates into a cylindrical shape to form a can body, and then applying a technique such as elaborate split mold and hydrostatic pressure press to the cylindrical can body portion in the circumferential direction. Manufactured with elongation strain. Problems that arise during the production include cracks, surface roughness, and changes in can dimensions.
In consideration of the above-mentioned problems, the characteristics required for the deformed three-piece can steel plate are listed as (1) to (4) below.
[0006]
(1) No reduction in dimensions in the can height direction. If there is a reduction in dimensions in the can height direction, it is difficult to secure the inner volume.
(2) No appearance defects such as rough skin and stretcher strain. If stretcher strain occurs in secondary molding after baking, the surface beauty is impaired.
[0007]
(3) There should be no cracks in the vicinity of the joint.
(4) It must have sufficient shape freezing property and can faithfully realize the target shape. If the shape freezing property is inferior, the amount of spring pack increases when the can body is formed into a cylinder, the roundness of the cylinder decreases, the variation in the joining allowance of the joint increases, and welding defects increase. Cracks may occur during processing.
[0008]
On the other hand, recently, there is a strong demand for reducing the plate thickness as one means of reducing the cost. This demand is not an exception even in the steel plate for deformed three-piece cans with complicated and severe secondary forming, but the required material properties are more It will be harsh.
In order to reduce the plate thickness and reduce the thickness of the steel plate for cans, it is necessary to make the steel plate harder from the viewpoint of securing the strength of the can body. Methods for hardening steel sheets include (1) solid solution strengthening by adding C, N, etc., (2) work hardening by secondary rolling after annealing, and (3) structure control by adding alloying elements. .
[0009]
However, in the method (1) by solid solution strengthening, conventionally, C and N having a high solid solution strengthening ability have been used, so that there was a problem that stretcher strain was generated on the surface of the steel sheet during the secondary forming, resulting in poor appearance. .
The method (2) by work hardening is the mainstream of the conventional strengthening method. However, as the thickness of the can body and the strength of the steel sheet increase, the secondary rolling reduction ratio after annealing increases, so that the yield stress increases and the shape freezeability deteriorates. . Further, the secondary rolling increases the anisotropy of the material, and in particular, the ductility in the direction perpendicular to the rolling becomes significantly smaller than that in the rolling direction. For this reason, there has been a problem that when the plate is cut so that the circumferential direction of the can is the direction perpendicular to the rolling direction of the steel plate, there is a risk of cracking due to low ductility during the flange processing.
[0010]
In the method (3) based on the structure control, the component elements in the steel are restricted for food hygiene, and it is not preferable to add excessive alloy elements.
For this reason, as an ultra-thin steel plate that can be used for a deformed three-piece can with severe secondary processing, it has the desired can strength, little dimensional change in the can height direction after deformation, and stretcher strain There has been a demand for a material that does not easily occur, that is, has low aging due to C, N, or the like.
[0011]
The present invention provides a deformed three-piece can steel plate that can solve the above-described problems, has excellent formability that can meet the demands of complex can designs, and can exhibit high yield, and a method for manufacturing the same. With the goal.
[0012]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-described problems, the present inventors have increased ductility anisotropy as a steel sheet strengthening method in order to prevent cracking at the joint during secondary processing of the can body. It has been found that it is advantageous to apply solid solution strengthening different from the conventional one in place of secondary rolling.
[0013]
In addition, to prevent the occurrence of rough skin and stretcher strain, the elongation at yield after aging treatment (210 ° C x 20 min) equivalent to painting and baking is less than 3%, and the aging index AI value is 30 MPa or less. For this purpose, the inventors have found that adjustment of the C, N and Al contents and addition of Mn, or further addition of B is effective. The AI value in the present invention refers to the amount of increase in yield stress before and after heat treatment of 100 ° C. × 30 min after applying 7.5% tensile prestrain.
[0014]
As a manufacturing method of the can body of the three-piece can, a method in which the rolling direction (L direction) of the steel plate is cylindrically formed so as to be the circumferential direction of the can (normal grain method) and a direction perpendicular to the rolling direction of the steel plate (C direction). There is a method (reverse grain method) in which a cylinder is formed so that is in the circumferential direction of the can.
When a can body of a deformed three-piece can is manufactured by the normal grain method, as shown in FIG. 4, the steel plate is stretched in the L direction by secondary forming after cylindrical forming. On the other hand, when manufactured by the reverse grain method, the steel sheet is stretched in the C direction. Therefore, the amount of shrinkage in the can height direction matches the amount of shrinkage in the direction perpendicular to the tensile direction at the time of secondary forming, and the amount of shrinkage in the specimen width direction when a tensile test is performed in the L or C direction of the steel sheet, That is, the correlation with the r value in the L or C direction is strong.
[0015]
Therefore, the change in the dimensions of the can body during secondary molding was investigated in detail using various materials. The result will be described.
The steel plate was picked up by a normal grain method and formed into a cylinder, and then the cylindrical can body was subjected to secondary forming as shown in FIG. 4B to obtain a deformed 3-piece can body. After secondary forming, the change in height of the can body is measured and shown in FIG. 1 in relation to the r value (L direction) of the steel sheet. From FIG. 1, it can be seen that it is effective to set the r value of the steel sheet in the range of 0.5 to 1.0 in order to ensure a small change in the can height direction and sufficient workability. The reverse grain method has the same tendency.
[0016]
Moreover, in order to make r value of a steel plate into the range of 0.5-1.0, as shown in FIG. 2, the knowledge that it was effective to make Mn content 0.3% or more was acquired.
Moreover, as shown in FIG. 3, when the Mn content is 0.3% or more, it has been found that the yield point elongation (Y-El) after aging treatment is 3% or less, and the aging property is also lowered. .
[0017]
The present invention has been further studied based on the above findings.
That is, the present invention is a mass%, C: 0.03~0.1%, Si : 0.10% or less, Mn: 0.3 ~1.5%, P : 0.04% or less, S: 0.01% or less, Al: 0.01 to 0.1%, N: containing 0.0030% or less, and a balance of Fe and unavoidable impurities, modifications rolling direction and the direction perpendicular to the rolling direction of the r values are all 0.5-1.0, and AI value is equal to or less than 30 MPa 3 It is a steel plate for piece cans.
[0018]
Further, the present invention is a mass%, C: 0.05 super ~0.1%, Si: 0.10% or less, Mn: 0.3 ~1.5%, P : 0.04% or less, S: 0.01% or less, Al: 0.01 to 0.1% , B: 0.0002 to 0.01%, N: 0.0030% or less, the balance being Fe and inevitable impurities, the r value in the rolling direction and the direction perpendicular to the rolling are both 0.5 to 1.0, and the AI value is 30 MPa or less a deformation 3-piece can for steel plate you wherein there, plate thickness is preferably not more than a very thin steel sheet 0.25 mm.
[0019]
Moreover, this invention is mass% , C : 0.03-0.1%, Si: 0.10% or less, Mn: 0.3-1.5%, P: 0.04% or less, S: 0.01% or less, Al: 0.01-0.1%, N : A steel material containing 0.0030% or less and the balance Fe and unavoidable impurities is heated at a heating temperature of 1050 to 1300 ° C, and then subjected to finish rolling at a finish rolling temperature of 800 to 1000 ° C, and wound. Temperature: After winding at 500 to 750 ° C, pickling and subsequent cold rolling, followed by continuous annealing at a temperature not lower than the recrystallization temperature and not higher than 720 ° C, followed by a reduction ratio of 1.0 to 10% It is a method for producing a steel sheet for a deformed three-piece can, wherein the r value in the rolling direction and the direction perpendicular to the rolling is 0.5 to 1.0, and the AI value is 30 MPa or less, characterized by performing secondary rolling. This is a method for producing an ultrathin steel sheet having a thickness of 0.25 mm or less.
[0020]
The present invention also provides a steel material containing, by mass%, C: more than 0.05 to 0.1%, Mn: 0.3 to 1.5%, Al: 0.01 to 0.1%, B: 0.0002 to 0.01%, N: 0.0030% or less. C: more than 0.05 to 0.1%, Si: 0.10% or less, Mn: 0.3 to 1.5%, P: 0.04% or less, S: 0.01% or less, Al: 0.01 to 0.1%, B: 0.0002 to 0.01% N: 0.0030% or less, the steel material having the balance Fe and unavoidable impurities is heated to a heating temperature of 1050 to 1300 ° C., and then subjected to finish rolling at a finishing rolling temperature of 800 to 1000 ° C., Winding temperature: After winding at 500 to 750 ° C, pickling and subsequent cold rolling, followed by continuous annealing at a temperature not lower than the recrystallization temperature and not higher than 720 ° C, followed by a reduction ratio of more than 8% 10% of the secondary rolling in the rolling direction and perpendicular to the rolling direction r value either 0.5-1.0 and wherein the performing, and deformation 3 peak AI values Ru der less 30MPa A method for producing cans steel plate, also preferably the following method for producing ultrathin steel sheet thickness 0.25 mm.
[0021]
In the present invention, the heating temperature is preferably maintained for 10 to 240 minutes, and the soaking time of the continuous annealing is preferably 60 seconds or less, preferably 5 seconds or more.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
First, the reasons for limiting the chemical composition of the steel sheet of the present invention will be described.
C: 0.03-0.1%
C is one of the important elements in the present invention from the viewpoint of the strength and aging of the steel sheet. In order to reduce aging, it is necessary to sufficiently precipitate cementite and reduce the amount of C dissolved in the steel. However, if the amount of C is less than 0.03%, the strength of the can is insufficient when thinned. On the other hand, if it exceeds 0.1%, it becomes excessively hard and formability deteriorates. In the present invention, B may be added from the viewpoint of reducing aging, but when C is added at 0.05% or less, the detailed mechanism is unknown, but either the L direction or the C direction. Therefore, when adding B, the amount of C must be 0.05% to 0.1%. If the amount of C in the steel increases, cementite precipitation nuclei increase and the diffusion distance of C during cementite precipitation can be shortened, thereby promoting precipitation of cementite and reducing aging.
[0023]
Si: 0.10% or less
When Si is added in a large amount, the surface treatment property and corrosion resistance deteriorate, so the upper limit was made 0.10%. In particular, when excellent corrosion resistance is required, the content is preferably 0.02% or less.
Mn: 0.3 to 1.5%
Mn is one of the important elements in the present invention. Mn is effective in strengthening the solid solution of steel, and is effective in responding to thinning. Further, Mn is effective in reducing aging and r value.
[0024]
It has been conventionally known that cementite precipitated in the hot rolling process is agglomerated and coarsened when the coiling temperature is high, thereby coarsening the crystal grains after cold rolling and annealing or increasing the r value. Therefore, it is considered that Mn is concentrated in cementite, slows the moving speed of the cementite-ferrite interface, suppresses aggregation and coarsening of cementite, and reduces the r value of the annealed plate. Moreover, it is thought that the increase in the solid solution Mn in the steel also contributes to the reduction of the r value.
[0025]
Part of the cementite precipitated in the hot rolling process is re-dissolved in the annealing process, but the migration speed of the cementite-ferrite interface is slowed due to the concentration of Mn in the cementite. Melting will be delayed. Therefore, it is considered that an increase in the amount of solute C in the annealing process is suppressed and aging is reduced.
[0026]
In order to exert these effects, Mn needs to be added at least 0.3% or more. On the other hand, if it exceeds 1.5% and it is added in a large amount, the corrosion resistance tends to deteriorate, and the steel plate is hardened to deteriorate the can-making processability. In addition, Preferably Mn is 0.5 to 1.0% from a viewpoint of aging reduction.
P: 0.04% or less P is a harmful element that hardens steel, deteriorates drawability and flange workability, and further deteriorates corrosion resistance. In particular, when the amount of P exceeds 0.04%, the effect becomes significant, so it is limited to 0.04% or less. In particular, when these characteristics are regarded as important, it is desirable to set it to 0.01% or less.
[0027]
S: 0.01% or less S is an element that exists as an inclusion in steel, lowers the ductility of the steel sheet, and further deteriorates the corrosion resistance, and is limited to 0.01% or less. In particular, in applications where workability is required, the content is preferably 0.005% or less.
Al: 0.01 to 0.1%
Al is an effective element for low aging because it fixes solute N in steel as AlN. For this purpose, Al requires addition of 0.01% or more. In addition, it is desirable to add 0.05% or more in the case of applications that are severe with respect to aging. On the other hand, if the content is too high, the occurrence frequency of surface defects due to alumina clusters and the like increases rapidly, so the upper limit was made 0.1%.
[0028]
N: 0.0030% or less N is an element that enhances aging, and is desirably reduced as much as possible in order to increase the frequency of stretcher strain generation. If it is limited to a range of 0.0030% or less, the above-described adverse effects can be suppressed and occurrence of practical problems can be prevented. The lower limit is not particularly limited, but if it is about 0.0010%, it can be said that it can be achieved economically and industrially. From the viewpoint of ensuring the stability of the material, the content is preferably 0.0020% or less.
[0029]
B: 0.0002 to 0.01%
B has the effect of making the crystal grains of the steel plate finer or suppressing the coarsening of the crystal grains in the heat-affected zone of the can weld zone, and fixing N to reduce aging. Such an effect is exhibited when 0.0002% or more is added. On the other hand, even if added over 0.01%, the effect tends to saturate, causing defects such as the occurrence of surface defects. For this reason, B was limited to the range of 0.0002 to 0.01%. In consideration of the stability of the material, B is preferably in the range of 0.0005 to 0.0050%.
[0030]
The balance consists of Fe and inevitable impurities, but even if a Trump element such as Sn is mixed in as impurities, it can be tolerated if it is 0.10% or less, and the influence on the use characteristics as a can can be ignored.
Next, limitation of manufacturing conditions will be described.
The molten steel having the above composition is melted by a normal melting method, and hot rolled on a steel material solidified by a continuous casting method or an ingot forming method. The steel material may be cooled to room temperature and then reheated, or may be charged and heated in a heating furnace without cooling.
[0031]
In the present invention, it is necessary to suppress the precipitation of MnS as much as possible and to concentrate Mn in the cementite. For this reason, it is preferable that the heating temperature of the steel material for hot rolling is high, and it is desirable that the steel material is heated and held at 1050 to 1300 ° C., preferably for 10 to 240 minutes. When the heating temperature is less than 1050 ° C., precipitation of MnS proceeds, Mn concentration in cementite is not achieved, and there is a risk of causing flaws at the edge of the steel sheet during subsequent rolling. On the other hand, when the heating temperature exceeds 1300 ° C., abnormal grain growth occurs and the structure becomes non-uniform, and the energy cost increases. For this reason, the heating temperature of a steel raw material shall be the range of 1050-1300 degreeC. Since the melting temperature of MnS is considered to be 1100 to 1150 ° C., the heating temperature is preferably 1150 ° C. or higher.
[0032]
If the holding time at the heating temperature is less than 10 minutes, the temperature in the steel material is not uniform, and rolling troubles such as sheet bar warping and bending frequently occur. Further, if it is maintained for more than 240 minutes, the precipitation of MnS proceeds and the expected effect of the present invention cannot be expected, and the structure of the final product is not uniform, and the scale loss due to the increase in scale thickness becomes remarkable. . For this reason, the holding time at the heating temperature is preferably in the range of 10 to 240 min. In view of material stability, it is more preferably 30 to 240 min.
[0033]
The steel material is hot rolled after heating. In hot rolling, finish rolling is performed at a finish rolling temperature of 800 to 1000 ° C.
If the finish rolling temperature is less than 800 ° C., it is difficult to refine the crystal grains of the final product, and the appearance beauty after canning is impaired. On the other hand, if the finish rolling exceeds 1000 ° C., the scale loss increases, which is not preferable. In addition, it is desirable to perform forced cooling after finish rolling. The forced cooling suppresses the in-plane anisotropy of the material and further improves the descaling property.
[0034]
The winding temperature is 500 to 750 ° C.
When the coiling temperature is less than 500 ° C., the material uniformity in the shape and width direction of the steel sheet is lowered, which is not preferable as an ultrathin steel sheet for cans. On the other hand, when the temperature exceeds 750 ° C., cementite is aggregated and coarsened, and the r value increases and the scale thickness increases. For this reason, winding temperature is limited to 500-750 degreeC. In order to fix the solid solution N as AlN and lower the aging property, it is desirable that the temperature be 600 to 700 ° C., more preferably 650 to 700 ° C.
[0035]
After hot rolling, pickling is performed.
The conditions for pickling are not particularly limited, and normal pickling with hydrochloric acid or sulfuric acid may be performed.
Following pickling, cold rolling is performed.
Cold rolling after pickling is called primary cold rolling in order to distinguish it from cold rolling after annealing. The conditions for primary cold rolling are not particularly limited. In the ultrathin steel sheet as in the present invention, rolling is usually performed at a rolling reduction of 75% or more, preferably 80% or more.
[0036]
After the primary cold rolling, annealing is performed.
For annealing, continuous annealing is performed at a temperature not lower than the recrystallization temperature and not higher than 720 ° C.
In order to obtain excellent secondary formability after cylindrical forming, the steel sheet needs to be annealed at a recrystallization temperature or higher to have a recrystallized structure. However, if annealing is performed at a high temperature exceeding 720 ° C., the high-temperature strength decreases during continuous annealing, and a shape defect phenomenon called a heat buckle often occurs in an ultrathin steel plate. Moreover, since cementite becomes easy to melt | dissolve, aging resistance deteriorates. For this reason, the annealing temperature is preferably not less than the recrystallization temperature and not more than 720 ° C. From the viewpoint of productivity, the recrystallization temperature is more preferably 700 ° C. or less.
[0037]
Furthermore, in the present invention, it is desirable that the soaking time for annealing is 60 sec or less, preferably 5 sec or more. When the soaking time is less than 5 seconds, the precipitation of cementite is insufficient. On the other hand, when it exceeds 60 seconds, the productivity decreases. In the present invention, a low-aging steel sheet can be produced without performing an overaging treatment. As an alternative to the overaging treatment, it is preferable to slow the cooling rate and lengthen the soaking time. Although an overaging treatment may be performed, for example, a temperature between 400 and 450 ° C. may be maintained for 5 seconds or more, or may be gradually cooled at 10 ° C./s or less. In actual production, it is preferable to perform annealing with a soaking time of 40 seconds or less in consideration of operational stability.
[0038]
Secondary annealing is performed after annealing.
The rolling reduction of secondary cold rolling is 1.0 to 10% for steel not containing B, and more than 8% to 10% for steel containing B. The secondary cold rolling needs to be performed at a reduction rate necessary to ensure the strength of the can body. In order to make the material of the annealed plate uniform and reduce aging by introducing movable dislocations, it is necessary to set the rolling reduction to at least 1.0%. In addition, since the r value tends to be high in steel to which B is added, in order to secure the r value of 1.0 or less, it is necessary to perform secondary cold rolling exceeding 8%. On the other hand, when the rolling reduction exceeds 10%, there are problems such as a large amount of springback at the time of cylindrical molding, a decrease in ductility, or an increase in ductility anisotropy and the occurrence of flange cracks. For this reason, the rolling reduction of the secondary cold rolling is limited to a range of 1.0 to 10% for steel not containing B, and more than 8% to 10% for steel containing B.
[0039]
The present invention is particularly suitable for application to an ultrathin steel plate of 0.25 mm or less.
Moreover, if it manufactures by applying above-mentioned conditions, the steel plate for cans suitable for a deformation | transformation 3 piece can will be obtained, and the r value of a rolling direction and a rolling right angle direction is 0.5-1.0 in both these steel plates for cans. In addition, even if it is formed into a deformed three-piece can, the AI value is 30 MPa or less, and the amount of shrinkage in the can axis direction is small, and the yield point elongation after baking coating is small and the aging property is low.
[0040]
By setting the r value in the rolling direction and the direction perpendicular to the rolling to 0.5 to 1.0, the shrinkage in the can axis direction can be minimized during the secondary forming of the cylindrical can body, and the yield of the steel material can be improved. . In this case, although the deformed portion is thinned, work hardening is added correspondingly, and there is no problem with the can body strength. Compared to the case where a steel plate having a large r value is used, it is desirable in terms of weight reduction of the can body.
[0041]
【Example】
Example 1
Molten steel having the composition shown in Table 1 was melted in a converter and made into a slab by a continuous casting method. These slabs (except steel Nos. 7 to 9) are subjected to hot rolling, primary cold rolling, continuous annealing, and secondary cold rolling shown in Table 2 to obtain an ultrathin steel plate with a final finished sheet thickness of 0.19 mm. did. Next, tin plating equivalent to No. 25 was continuously applied on a halogen type electric tin plating line to finish it with a tinplate. For these tin-plated steel sheets, the tensile strength (TS) in the rolling direction (L direction) and the direction perpendicular to the rolling direction (C direction), the r value, and the elongation at yield after aging treatment (210 ° C. × 20 min) (Y-El) ) And AI values. The AI value was measured as the amount of increase in yield stress before and after heat treatment after applying a heat treatment of 100 ° C. × 30 min after applying 7.5% tensile prestrain. The test piece used was a JIS No. 13 test piece.
[0042]
[Table 1]
[0043]
[Table 2]
[0044]
Next, these steel plates were cylindrically formed into a 250 g can size, and then subjected to secondary forming using a press jig having a special split mold structure. The direction of tensile strain in secondary forming was the steel plate L direction, and the amount of elongation strain was 7% on average.
After making the can, the welded part, the weld heat-affected part, and other parts were evaluated for the presence of cracks and the appearance defects. Appearance defects are evaluated for the occurrence of stretcher strain, ridging, rough skin, and the like. Moreover, the height change of the can axis direction was investigated before and after secondary molding. These results are shown in Table 3.
[0045]
[Table 3]
[0046]
From Table 3, the inventive example has a higher tensile strength and an r value adjusted to an appropriate range of 0.5 to 1.0 as compared with the comparative example, and has low aging, and further, no cracking occurs after secondary molding. It can be seen that the surface appearance is good and the change in can height due to secondary molding is small. In this invention, a blank shape can be made smaller and a yield is improved.
(Example 2)
Using No.3 steel and No.7-9 steel of Table 1, it carried out similarly to Example 1, and was set as the steel plate of final finishing board thickness 0.22mm on the conditions shown in Table 4. Next, these steel sheets were continuously plated with tin corresponding to No. 25 on a halogen-type electric tin plating line, and finished with a tinplate. For these tin-plated steel plates, the mechanical properties and can characteristics of the steel plates were investigated in the same manner as in Example 1. Note that the can body forming plate was set so that the can axis direction was the L direction.
[0047]
These results are shown in Table 5.
[0048]
[Table 4]
[0049]
[Table 5]
[0050]
From Table 5, the present invention example has a higher tensile strength and an r value adjusted to an appropriate range of 0.5 to 1.0 as compared with the comparative example, and is low in aging, and further, no cracking occurs after secondary molding. It can be seen that the surface appearance is good and the change in can height due to secondary molding is small. In the present invention, the blank shape can be made smaller, and the yield is improved by about 2%. When the production volume is large, the economic effect due to yield improvement becomes significant.
[0051]
In addition, the steel plate for cans obtained by the present invention is not limited to the above-described tin plating, but is a tin-free steel plate, a composite plated steel plate, an oil-coated steel plate to which plating is not applied, or a steel plate having a resin film adhered to the surface of the steel plate. The same effect can be obtained.
Moreover, there is no problem even if it uses as a steel plate for 2 piece cans besides the steel plate for 3 piece cans.
[0052]
【The invention's effect】
According to the present invention, the aging property is low, the surface beauty after can molding and baking coating is excellent, and the amount of shrinkage in the can axis direction that occurs when producing a deformed three-piece can can be reduced, thereby improving the material yield. It is possible to achieve a remarkable industrial effect.
[Brief description of the drawings]
FIG. 1 is a graph showing an influence of a rolling direction r value of a steel sheet on a change in can height after secondary forming.
FIG. 2 is a graph showing the influence of Mn content on yield point elongation after aging treatment.
FIG. 3 is a graph showing the influence of the Mn content on the r value in the L direction of the steel sheet.
FIG. 4 is an explanatory diagram showing a state of secondary molding processing that gives tensile strain in the circumferential direction after cylindrical molding.

Claims (4)

In mass%,
C: 0.03-0.1%, Si: 0.10% or less,
Mn: 0.3 to 1.5%, P: 0.04% or less,
S: 0.01% or less, Al: 0.01 to 0.1%,
N: containing 0.0030% or less, and a balance of Fe and unavoidable impurities, modifications rolling direction and the direction perpendicular to the rolling direction of the r values are all 0.5-1.0, and AI value is equal to or less than 30 MPa 3 Steel plate for piece cans. In mass%,
C: more than 0.05 to 0.1%, Si: 0.10% or less,
Mn: 0.3 to 1.5%, P: 0.04% or less,
S: 0.01% or less, Al: 0.01 to 0.1%,
B: 0.0002 to 0.01%, N: 0.0030% or less, remaining Fe and inevitable impurities, r value in the rolling direction and in the direction perpendicular to the rolling is 0.5 to 1.0, and AI value is 30 MPa or less A modified three-piece steel plate for cans. % By mass
C: 0.03 to 0.1%, Si : 0.10 % or less, Mn: 0.3 to 1.5%, P: 0.04 % or less, S: 0.01 % or less, Al: 0.01 to 0.1%, N: 0.0030% or less , balance Fe And a steel material having a composition composed of unavoidable impurities was heated to a heating temperature of 1050 to 1300 ° C., and then subjected to finish rolling at a finishing rolling temperature of 800 to 1000 ° C. and wound at a winding temperature of 500 to 750 ° C. After that, pickling and subsequent cold rolling, followed by continuous annealing at a temperature not lower than the recrystallization temperature and not higher than 720 ° C, followed by secondary rolling at a rolling reduction of 1.0 to 10% A method for producing a steel sheet for a deformed three-piece can in which the r value in the rolling direction and the direction perpendicular to the rolling is 0.5 to 1.0 and the AI value is 30 MPa or less. In mass%,
C: More than 0.05 to 0.1%, Mn: 0.3 to 1.5%, Al: 0.01 to 0.1%, B: 0.0002 to 0.01%, N: 0.0030% or less steel material is heated to heating temperature: 1050 to 1300 ° C Thereafter, finish rolling is performed at a finish rolling temperature of 800 to 1000 ° C., winding at a winding temperature of 500 to 750 ° C., pickling and subsequent cold rolling, and then a recrystallization temperature of 720 ° C. or higher. After performing continuous annealing at the following temperatures, the rolling reduction and the r-value in the direction perpendicular to the rolling are 0.5 to 1.0, characterized by performing secondary rolling at a reduction ratio of more than 8% to 10%, and AI. A method for producing a steel plate for a modified 3-piece can having a value of 30 MPa or less.