CN116657048A

CN116657048A - Steel sheet for cans and method for producing same

Info

Publication number: CN116657048A
Application number: CN202310766077.9A
Authority: CN
Inventors: 斋藤勇人; 假屋房亮; 小岛克己
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2019-03-29
Filing date: 2020-03-06
Publication date: 2023-08-29
Also published as: KR20210141612A; TW202100759A; JPWO2020203052A1; CN113490760A; KR102677317B1; WO2020203052A1; TWI728760B; JP6822617B1; CN113490760B

Abstract

The present application provides a steel sheet for cans suitable for use as a can container material for food and beverage cans, and a method for producing the same. The steel sheet for cans of the present application has the following composition: contains C in mass%: 0.010-0.080%, si: less than 0.05%, mn:0.10 to 0.70 percent, P: less than 0.03%, S: less than 0.020%, al: 0.005-0.020% and N: 0.0120-0.0180%, the remainder being Fe and unavoidable impurities, Δr being-0.3.

Description

Steel sheet for cans and method for producing same

The present application is a divisional application filed for the application of the application of the steel sheet for cans and the manufacturing method thereof, which has the application date of 2021, the year 08, the month 27, the application number of 202080017314.6.

Technical Field

The present application relates to a steel sheet for cans suitable for use as a can container material for food and beverage cans, and a method for producing the same. The present application relates to a steel sheet for cans, which is suitable for use as a bayonet cap and a screw cap for a DRD (deep drawing) can body and a bottle cap, and a method for manufacturing the same.

Background

Among steel sheets used for beverage cans and food cans, steel sheets called DR (Double Reduced) materials are sometimes used for can lids, can bottoms, 3-piece can bodies, and the like. The DR material is a steel sheet produced by performing primary cold rolling, annealing, and then performing secondary cold rolling at a rolling reduction of a predetermined or higher. Compared with SR (Single Reduced) materials which are subjected to temper rolling only with a small rolling yield, the sheet thickness can be easily Reduced while hardening. From the viewpoint of reducing environmental load and cost in recent years, it is demanded to reduce the amount of steel sheet used for beverage cans and food cans, and DR materials which are easy to thin steel sheets are increasingly desired.

DR materials are mainly hardened by processing and curing, and therefore generally have low stretch formability. Therefore, there are the following problems: defects such as cracks occur in the rivet portion of EOE (Easy-Open End) or in the portion requiring high stretch formability such as flange processing of 3-piece can body. In this regard, steel sheets with improved drawability have been proposed.

For example, patent document 1 discloses a steel sheet for high-strength containers, which contains, in mass%, C:0.01 to 0.05 percent of Si: less than 0.04%, mn:0.1 to 1.2 percent, S: less than 0.10%, al:0.001 to 0.100 percent, N: less than 0.10%, P:0.0020 to 0.100%, the balance being Fe and unavoidable impurities, the tensile strength TS being 500MPa or more and the difference in endurance between the width direction of the sheet and the rolling direction being 20MPa or less.

Further, for example, patent document 2 discloses a high-strength steel sheet having a composition containing, in mass%, C:0.010% -0.080%, si: less than 0.05%, mn:0.10% -0.70%, P: less than 0.03%, S:0.020% by weightLower, al:0.005% -0.070%, N:0.0120% -0.0180%, the remainder is composed of Fe and unavoidable impurities, wherein the N content as solid solution N is 0.0100% or more, the average ferrite grain size is 7.0 μm or less, and the dislocation density at 1/4 depth position of plate thickness from the surface is 4.0X10 ¹⁴ m ^-2 ～2.0×10 ¹⁵ m ^-2 The tensile strength in the transverse direction of rolling after aging treatment is 530MPa or more, and the elongation is 7% or more.

Prior art literature

Patent literature

Patent document 1: WO2009/125876

Patent document 2: WO2015/166646

Disclosure of Invention

In the technique described in patent document 1, good flange workability and necking workability are obtained, but drawing formability required for processing into, for example, a DRD can body, a screw cap, or the like is insufficient. For example, when a steel sheet is drawn into a can body, it is desirable that the projection (flange width) of the flange portion after the forming be uniform in the circumferential direction of the can body. There is a need for providing a steel sheet for cans which has little circumferential variation in the width of the flange and is excellent in drawing formability. In addition, the tensile strength of the technique described in patent document 1 is about 640MPa, and the strength of the steel sheet is insufficient for a thin-walled product to have sufficient compressive strength.

Similarly, the drawing formability of the technique described in patent document 2 is also insufficient.

The present application has been made in view of such circumstances, and an object thereof is to provide a high-strength steel sheet for cans excellent in drawability and a method for producing the same. The high strength means that the tensile strength in the rolling direction after aging treatment is 650MPa or more.

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the inventors have newly found that focusing on the influence of the in-plane anisotropy Δr of the r value of the steel sheet on the drawing formability of the steel sheet for cans, if the Δr of the steel sheet is from-0.3 to 0.3, excellent drawing formability can be obtained. The inventors of the present application have found that a steel sheet for cans having a Δr of-0.3 to 0.3 can be provided by setting the conditions of steel components, slab heating, hot rolling, coiling, primary cold rolling, annealing, and secondary cold rolling to predetermined ranges. Then, the present application has been completed based on this knowledge.

In the present specification, "r value" means lankford value indicating a plastic strain ratio. In the present specification, "Δr" can be calculated according to the following expression.

The present application has been completed based on the above-described findings, and has the following gist.

(1) A steel sheet for cans having the following composition,

contains C in mass%: 0.010% -0.080%, si: less than 0.05%, mn:0.10% -0.70%, P: less than 0.03%, S: less than 0.020%, al:0.005% -0.020% and N:0.0120% -0.0180%, and the balance of Fe and unavoidable impurities;

the in-plane anisotropy Deltar of r value is-0.3 to 0.3.

(2) The steel sheet for cans according to the above (1), wherein the steel sheet contains, in mass%, ti in addition to the above composition: 0.005-0.020%, nb: 0.005-0.020%, mo:0.01 to 0.05 percent of Cr:0.04 to 0.10 percent, B:0.0005 to 0.0060 percent, ca:0.0010 to 0.01 percent of Ni:0.05 to 0.15 percent of Cu:0.05 to 0.20 percent of one or more than one kind of the components.

(3) A method for manufacturing a steel sheet for cans, comprising the steps of: heating the slab having the composition of the above (1) or (2) to 1180 ℃ or higher; hot rolling the heated slab at a finish rolling temperature of 820 ℃ or higher; a step of winding the hot rolled sheet at a temperature exceeding 640 ℃ and 700 ℃ or lower; a step of performing primary cold rolling on the rolled hot-rolled sheet at a rolling rate of 85% or more; and annealing the cold-rolled sheet subjected to primary cold rolling at 620-690 ℃ and performing secondary cold rolling on the annealed sheet at a rolling rate exceeding 20% and not more than 40%.

According to the present application, a high-strength steel sheet for cans having an in-plane anisotropy Δr of-0.3 to 0.3 and excellent drawing formability can be provided. By using the steel sheet for cans of the present application, cans and covers can be produced from a DR steel sheet having a small thickness, which can reduce the cost and the cost of resources, and thus can exhibit remarkable industrial effects.

Detailed Description

The present application will be described in detail below. The steel sheet for cans of the present application is characterized by comprising the following components: contains C in mass%: 0.010% -0.080%, si: less than 0.05%, mn:0.10% -0.70%, P: less than 0.03%, S: less than 0.020%, al:0.005% -0.020% and N:0.0120% -0.0180%, and the balance of Fe and unavoidable impurities;

the in-plane anisotropy Deltar of r value is-0.3 to 0.3.

The steel sheet for cans of the present application can be produced as follows: the slab having the above composition is heated to 1180 ℃ or higher, hot-rolled at a finishing temperature of 820 ℃ or higher, coiled at a temperature of more than 640 ℃ and 700 ℃ or lower, cold-rolled at a rolling rate of 85% or higher, annealed at 620 ℃ to 690 ℃, and cold-rolled at a rolling rate of more than 20% and 40% or lower.

First, the composition of the steel sheet for cans of the present application will be described.

C：0.010％～0.080％

C is an important element for improving strength, and setting to 0.010% or more contributes to high strength, specifically, to a tensile strength of 650MPa or more in the rolling direction after aging treatment. The amount of C is preferably 0.020% or more. On the other hand, if the C content exceeds 0.080%, the in-plane anisotropy Δr of r value is lower than-0.3, and the drawing formability is lowered, so that the upper limit of the C content needs to be 0.080% or less. The amount of C is preferably 0.040% or less.

Si: less than 0.05%

If Si is added in a large amount, si surface treatment property is deteriorated due to surface enrichment, and corrosion resistance is lowered, so that the Si amount needs to be 0.05% or less, preferably 0.03% or less. On the other hand, si contributes to improvement of tensile strength, so the lower limit of Si is preferably set to 0.01%.

Mn：0.10％～0.70％

Mn has the effect of improving the tensile strength of a steel sheet by solid solution strengthening and the effect of preventing reduction in hot-rolling properties due to S contained in the steel by forming MnS. In order to obtain this effect, it is necessary to add Mn of 0.10% or more. In particular, from the viewpoint of increasing the strength of the steel sheet, mn is preferably added at 0.20% or more, and more preferably at 0.50% or more. On the other hand, if Mn exceeds 0.70%, in-plane anisotropy deteriorates. Therefore, the Mn content is set to 0.70% or less. The Mn content is preferably 0.65% or less.

P: less than 0.03%

If P is added in a large amount, the formability of the steel sheet decreases due to excessive hardening and segregation of P to the center of the steel sheet, and the corrosion resistance decreases. Therefore, the upper limit of the amount of P is set to 0.03%. The amount of P is preferably 0.02% or less. The reduction of the P content to less than 0.01% is accompanied by an increase in costs such as smelting costs. Therefore, the amount of P is preferably 0.01% or more from the viewpoint of economy.

S: less than 0.020%

S forms sulfides in the steel, which reduces hot rolling properties and reduces hot rolling workability. Therefore, the upper limit of the S amount is set to 0.020% or less. The S content is preferably 0.015% or less. It should be noted that if the S amount is 0.008% or more, pitting corrosion can be prevented regardless of the content of the can, and therefore the S amount is preferably 0.008% or more.

Al：0.005％～0.020％

Al is an element added as a deoxidizer. To obtain this effect, it is necessary to add 0.005% or more of Al. When Al is excessively present in the steel, alN is formed by bonding with N, and solid solution N in the steel is reduced, resulting in a decrease in tensile strength of the steel sheet. Therefore, the amount of Al needs to be 0.020% or less. The amount of Al is preferably 0.008 to 0.019%, more preferably 0.011 to 0.016%. The Al content is preferably 0.008% or more, more preferably 0.011% or more, still more preferably 0.019% or less, still more preferably 0.016% or less.

N：0.0120％～0.0180％

N is a solid solution strengthening element and contributes to the high strength of the steel sheet. For this effect, it is necessary to add 0.0120% or more as the N amount. On the other hand, if N is added in a large amount, the in-plane anisotropy Δr of the r value is significantly reduced, and the drawing formability is reduced, so that the upper limit of the N amount is set to 0.0180%. Preferably, the N content is 0.0135% -0.0165%. The amount of N is preferably 0.0135% or more, and preferably 0.0165% or less.

The steel sheet for cans of the present application has a composition of components including the above components and the balance being Fe and unavoidable impurities as essential components.

The steel sheet for cans of the present application may contain, as required, ti in addition to the above basic components: 0.005% -0.020%, nb:0.005% -0.020%, mo:0.01% -0.05%, cr:0.04% -0.10%, B:0.0005% -0.0060%, ca:0.0010 to 0.01 percent of Ni:0.05 to 0.15 percent of Cu:0.05 to 0.20 percent of more than one kind of the components.

Ti：0.005％～0.020％

Ti is a precipitation strengthening element and contributes to the high strength of the steel sheet. For this effect, 0.005% or more of Ti is preferably added. On the other hand, if a large amount of Ti is added, the anisotropy of the steel sheet is excessively large, and therefore the Ti amount is preferably 0.020% or less.

Nb：0.005％～0.020％

Nb contributes to the high strength of the steel sheet as a precipitation strengthening element. For this effect, it is preferable to add 0.005% or more of Nb. On the other hand, if Nb is added in a large amount, the anisotropy of the steel sheet is too large, and thus is preferably 0.02% or less.

Mo：0.01％～0.05％

Mo acts as a precipitation strengthening element, and further, by refining the structure, it contributes to the enhancement of strength of the steel sheet. For this effect, mo is preferably added at 0.01% or more. However, even if Mo is added in a large amount, the effect is saturated, so that the Mo amount is preferably 0.05% or less.

Cr：0.04％～0.10％

Cr is a precipitation strengthening element and contributes to the high strength of the steel sheet. For this effect, cr is preferably added at 0.04% or more. When a large amount of Cr is added, the effect of increasing the strength by forming coarse precipitates is saturated, and therefore the Cr amount is preferably 0.10% or less.

B：0.0005％～0.0060％

B contributes to the high strength of the steel sheet by grain refining. For this effect, it is preferable to add 0.0005% or more of B. Even if B is added in a large amount, not only the effect is saturated, but also the absolute value of the in-plane anisotropy Δr of the r value of the steel sheet becomes large, so that the B amount is preferably 0.0060% or less.

Ca：0.0010％～0.01％

Ca has an effect of improving hot-rolling property by refining sulfide. In addition, ca has the following effects: the combination of Ca and S reduces the amount of Mn in the resultant compound MnS and increases the ratio of the amount of Mn contributing to solid solution strengthening, thereby contributing to the enhancement of strength of the steel sheet. Therefore, 0.0010% or more of Ca is preferably added. Even if Ca is added in a large amount, the effect is saturated, and coarse inclusions may be formed, and the drawing formability may be deteriorated. Therefore, the Ca content is preferably 0.01% or less.

Ni：0.05％～0.15％

Ni contributes to the high strength of the steel sheet by solid solution strengthening and grain refining. For this effect, ni is preferably added at 0.05% or more. When a large amount of Ni is added, the deterioration of the surface properties is remarkable, and therefore the Ni amount is preferably 0.15% or less.

Cu：0.05％～0.20％

Cu contributes to the high strength of the steel sheet by solid solution strengthening and grain refining. For this effect, cu is preferably added at 0.05% or more. When the Cu is added in a large amount, the deterioration of the surface properties is remarkable, and therefore the Cu content is preferably 0.20% or less, more preferably 0.15% or less.

Next, the material properties of the steel sheet for cans of the present application will be described.

In-plane anisotropy Δr of r value: -0.3 to 0.3

In order to form a DRD can or bottle cap with good drawability, it is necessary that Δr, which is an index of in-plane anisotropy of r value, is-0.3 to 0.3. Here, Δr is represented by Δr= (r ₀ +r ₉₀ －2·r ₄₅ ) And/2. The more Δr deviates from the above range, the r valueThe larger the anisotropy is, the larger the so-called "ear" of the flange portion is at the time of drawing, and thus a good shape cannot be obtained. That is, if Δr deviates from the above range, the variation in width of the flange portion after the drawing becomes large, and thus sound drawing of the shape of the uniform flange width cannot be achieved in the steel sheet for a can.

Δr is preferably from-0.25 to 0.25.

Tensile strength in rolling direction after aging: 650MPa or more

In order to secure the compressive strength of the DRD can body and the bottle cap, the tensile strength of the steel sheet in the rolling direction is preferably 650MPa or more. By setting the tensile strength to 650MPa or more, sufficient compressive strength can be ensured even if the steel sheet is thinned. In the case of DR materials, the tensile strength in the rolling direction is generally lower than that in the direction perpendicular to rolling, and therefore, in this specification, the tensile strength in the rolling direction is evaluated. In addition, since steel sheets for cans are often used after baking and coating, in the present specification, the properties after aging treatment at 210 ℃ for 10 minutes, which corresponds to baking and coating, are evaluated. When the sheet thickness is made particularly thin, the tensile strength of the steel sheet in the rolling direction is preferably 680MPa or more. On the other hand, in the case of excessively increasing the strength, occurrence of molding failure such as wrinkles becomes remarkable at the time of molding, and therefore, the tensile strength is preferably 800MPa or less.

Next, a method for manufacturing a steel sheet for cans according to the present application will be described.

The steel sheet for cans of the present application can be produced by the following steps: a step of heating a slab having the above composition to 1180 ℃ or higher, a step of hot-rolling the heated slab at a finish rolling temperature of 820 ℃ or higher, a step of winding a hot-rolled sheet at a temperature of more than 640 ℃ and 700 ℃ or lower, a step of primary cold-rolling the wound hot-rolled sheet at a rolling rate of 85% or higher, a step of annealing the primary cold-rolled sheet at 620 ℃ to 690 ℃, and a step of secondary cold-rolling the annealed sheet at a rolling rate of more than 20% and 40% or lower.

Heating temperature: 1180deg.C or higher

If the heating temperature of the slab before hot rolling is too low, a part of AlN is not melted, the amount of solid-solution N decreases, and the tensile strength decreases. Therefore, in the step of heating the slab, a heating temperature of 1180 ℃ or higher is required. Preferably, the heating temperature is 1200 ℃ or higher. The upper limit of the heating temperature is not particularly limited, but if it is 1300 ℃ or less, surface defects due to scale are easily avoided, so the upper limit is preferably 1300 ℃.

Finishing temperature: 820 ℃ or above

If the finishing temperature in the hot rolling step is less than 820 ℃, the Δr is outside the predetermined range, and the drawability is deteriorated. Therefore, the finishing temperature needs to be 820 ℃ or higher. The preferable finishing temperature is 860 ℃ or higher. The upper limit of the finishing temperature is not particularly limited, but if it is 930 ℃ or lower, a steel sheet having a finer grain size can be obtained, which is preferable.

Winding temperature: above 640 ℃ and below 700 DEG C

If the coiling temperature in the coiling step is 640 ℃ or lower, the cementite formation in the steel is insufficient, and the cold rolling in the next step is performed in a state where the solid solution C is excessive, so that the Δr becomes a value out of the predetermined range, and the drawing formability is deteriorated. Therefore, the winding temperature needs to exceed 640 ℃. The winding temperature is preferably 650 ℃ or higher. On the other hand, if the coiling temperature exceeds 700 ℃, the grain size of the hot rolled sheet becomes coarse, and thus the grain size of the final steel sheet is also coarse, and the tensile strength is lowered. Therefore, the winding temperature needs to be 700 ℃ or lower. The winding temperature is preferably 680 ℃ or lower.

Here, before cold rolling, acid washing may be performed as needed. The pickling conditions are not particularly limited as long as the surface scale of the hot rolled sheet can be removed. Therefore, the acid washing is carried out according to a conventional method.

Primary cold rolling rate: more than 85 percent

In order to refine the grain size of the annealed ferrite and to improve the tensile strength, the rolling ratio in the primary cold rolling step needs to be 85% or more. The rolling percentage is preferably 86% or more. On the other hand, if the rolling reduction is 91.4% or less, it is easy to control the Δr to be small, and therefore preferable. Further, the total rolling reduction of the primary cold rolling and the secondary cold rolling described later is preferably 90.5% or less, more preferably 90.0% or less.

Annealing temperature: 620-690 DEG C

In order to secure drawing formability, it is necessary to sufficiently recrystallize in annealing. For this reason, in the step of annealing the cold-rolled sheet obtained in the primary cold-rolling step, the annealing temperature needs to be 620 ℃ or higher. On the other hand, if the annealing temperature is too high, the ferrite grain size coarsens and the tensile strength decreases. Therefore, the annealing temperature needs to be 690 ℃. The annealing temperature is preferably 640 ℃ or higher, preferably 680 ℃ or lower, and more preferably 640 ℃ to 680 ℃. The annealing time is preferably 10 seconds or longer. The annealing method is not limited, but a continuous annealing method is preferably used from the viewpoint of uniformity of the material. Further, the cooling condition after annealing is not particularly limited, but from the viewpoint of increasing the strength by the action of solid solution C, it is more preferable to cool at a cooling rate of 50 ℃/sec or more in a temperature range of 500 ℃ to 300 ℃ after annealing.

Secondary cold rolling rate: more than 20% and less than 40%

The annealed sheet obtained after the annealing is strengthened by secondary cold rolling, and is processed into a sheet-thick steel sheet. In order to set the tensile strength of the steel sheet after aging to 650MPa or more in the rolling direction, the rolling rate in the secondary cold rolling step needs to be set to be more than 20%. The rolling rate is preferably 22% or more. On the other hand, if the secondary cold rolling ratio is too high, the drawing formability is deteriorated. Therefore, the rolling reduction is required to be 40% or less. In particular, when high drawability is required, the rolling reduction is preferably set to 35% or less.

The steel sheet for cans of the present application can be obtained by the above method. Even if the steel sheet obtained here is subjected to surface treatment such as plating and chemical conversion treatment, the effect of the application is not lost.

Examples

Steel containing the components indicated by steel symbols a to V in table 1 and the remainder consisting of unavoidable impurities and Fe was melted to obtain a billet. The resulting billets were heated under the conditions shown in table 2, hot rolled and coiled, after which the scale was removed by pickling, cold rolled once, and annealed at each annealing temperature in a continuous annealing furnace. The obtained annealed sheet was subjected to secondary cold rolling at respective secondary cold rolling rates to obtain steel sheets (steel sheets 1 to 29) having a sheet thickness of 0.12 to 0.22 mm.

TABLE 1

Steel symbol	C	S	Mn	P	S	Al	N	Others	Remarks
										A	0.032	0.01	0.25	0.011	0.011	0.016	0.0151	-	Inventive example
B	0.020	0.02	0.30	0.014	0.01-2	0.016	0.0139	-	Inventive example
										C	0.039	0.01	0.14	0.009	0.013	0.010	0.0163	-	Inventive example
D	0.040	0.01	0.50	0.013	0.010	0.018	0.0121	-	Inventive example
										E	0.026	0.01	0.70	0.009	0.008	0.008	0.0175	-	Inventive example
F	0.080	0.01	0.38	0.010	0.009	0.019	0.0136	-	Inventive example
										G	0.012	0.01	0.23	0.013	0.010	0.014	0.0152	-	Inventive example
H	0.046	0.01	0.24	0.014	0.011	0.016	0.0136	-	Inventive example
										I	0.023	0.01	0.63	0.014	0.009	0.018	0.0157	-	Inventive example
J	0.033	0.01	0.52	0.011	0.010	0.016	0.0158	-	Inventive example
										K	0.084	0.01	0.36	0.013	0.012	0.014	0.0142	-	Comparative example
L	0.005	0.01	0.23	0.014	0.011	0.015	0.0147	-	Comparative example
										M	0.033	0.01	023	0.008	0.012	0.013	0.0191	-	Comparative example
N	0.035	0.01	0.36	0.010	0.008	0.080	0.0032	-	Comparative example
										O	0.032	0.01	0.23	0.012	0.011	0.018	0.0156	Ti：0.009	Inventive example
P	0.035	0.01	0.23	0.016	0.011	0.014	0.0150	Nb：0.014	Inventive example
										Q	0.029	0.01	0.25	0.016	0.013	0.016	0.0147	Mo：0.03	Inventive example
R	0.030	0.01	0.25	0.012	0.012	0.019	0.0153	Cr：0.08	Inventive example
										S	0.033	0.01	0.25	0.013	0.010	0.009	0.0142	B：0.0024	Inventive example
T	0.030	0.01	0.33	0.015	0.012	0.015	0.0161	Ca：0.0034	Inventive example
										U	0.028	0.01	0.31	0.019	0.010	0.016	0.0155	Ni：0.09	Inventive example
V	0.034	0.01	0.30	0.011	0.011	0.017	0.0141	Cu：0.11	Inventive example

(mass%)

Tensile Strength in the Rolling direction after aging

After the aging treatment corresponding to the baking coating was performed at 210℃for 10 minutes, the tensile strength was evaluated according to JIS Z2241 by the No. 5 tensile test defined in JIS Z2241 so that the tensile direction became the rolling direction.

In-plane anisotropy Δr of r value

The in-plane anisotropy Δr of the r value was measured and evaluated by the natural vibration method (module r) described in ASTM a 623M.

Deep drawing formability

Blank was punched out of the steel sheet obtained with a diameter of 160mm, and a can body with a diameter of 82.8mm and a height of 45.5mm was produced by drawing-redraw forming. Further, a bar-shaped projection having diameters of 70mm and 40mm (depth 0.5mm, radius of curvature 1 mm) was formed on the bottom of the can. The flange width of the obtained can body was measured at 15 degree intervals throughout the circumference. If the difference between the maximum value and the minimum value of the flange width is 1.5mm or less, the excellent drawing formability is marked as excellent, if it exceeds 1.5mm and 2mm or less, the acceptable drawing formability is marked as good, and if it exceeds 2mm, the poor drawing formability is marked as poor.

The detailed conditions for this test are described below.

Lubrication conditions: coating lubricating oil on both surfaces of steel plate

Drawing ratio of the first drawing: 1.52

Second drawing ratio: 1.26

Fold suppression pressure for each draw: 0.3MPa

Shoulder radius of die at first draw: 2.5mm

Shoulder radius of die at second draw: 2.5mm

Compressive Strength

The lid was screwed on the can body, and air was introduced under sealing from the lid side, and the pressure at which the bottom of the can was bent was measured, and if the pressure was 0.18MPa or more, the pressure was marked as o, and if the pressure was less than 0.18MPa, the pressure was marked as x.

The test results are shown in Table 3. The in-plane anisotropy Deltar of the r value of the inventive examples is-0.3 to 0.3, and the drawing formability and the compressive strength are excellent. On the other hand, in the comparative example, any one or more of the above characteristics were poor.

TABLE 3

TABLE 3 Table 3

Deep drawing formability for the rare earth 1

And (3) the following materials: 1.5mm or less

O: more than 1.5mm and less than 2.0mm

X: exceeding 2.0mm

Compression strength of 2

O: 0.18MPa or more

X: less than 0.18MPa

Claims

1. A steel sheet for cans, comprising the following components: contains C in mass%: 0.010% -0.080%, si: less than 0.05%, mn:0.10% -0.70%, P: less than 0.03%, S: less than 0.020%, al:0.005% -0.020% and N:0.0120% -0.0180%, and the balance of Fe and unavoidable impurities;

the in-plane anisotropy Deltar of the r value is-0.30 to 0.30.

2. The steel sheet for cans according to claim 1, wherein the steel sheet contains, in mass%, ti: 0.005-0.020%, nb: 0.005-0.020%, mo:0.01 to 0.05 percent of Cr:0.04 to 0.10 percent, B:0.0005 to 0.0060 percent, ca:0.0010 to 0.01 percent of Ni:0.05 to 0.15 percent of Cu:0.05 to 0.20 percent of one or more than one kind of the components.