Abstract: A method for manufacturing a high-strength steel sheet for a can, including (a) hot rolling a steel slab at a slab extraction temperature of 1200° C. or more and a finish rolling temperature of (Ar3 transformation temperature?30)° C. or more, the steel slab containing, on the basis of mass percent, more than 0.02%, but 0.10% or less of C, 0.10% or less of Si, 1.5% or less of Mn, 0.20% or less of P, 0.20% or less of S, 0.10% or less of Al, 0.0120% to 0.0250% of N, and the balance being Fe and incidental impurities; (b) coiling at a temperature of 650° C. or less; (c) pickling; (d) carrying out a first cold rolling; (e) continuously annealing; and (f) carrying out a second cold rolling at a reduction ratio of 10% or more and less than 20%.

Abstract: A steel sheet for containers that has a hardness of 500 MPa or more and superior workability and a method for producing the steel sheet are provided. A steel containing, in percent by mass, 0.01% to 0.05% carbon, 0.04% or less silicon, 0.1% to 1.2% manganese, 0.10% or less sulfur, 0.001% to 0.100% aluminum, 0.10% or less nitrogen, and 0.0020% to 0.100% phosphorus, the balance being iron and incidental impurities, is subjected to hot rolling at a finishing temperature of (Ar3 transformation temperatute?30)° C. or more and a coiling temperature of 400° C. to 750° C., is subjected to pickling and cold rolling, is subjected to continuous annealing including overaging treatment, and is subjected to second cold rolling at a reduction rate of 20% to 50%, thus providing a high-strength steel sheet for containers that has a tensile strength of 500 MPa or more and a proof stress difference between width and rolling directions of 20 MPa or less.

Abstract: A steel sheet for cans that has a yield stress of at least 500 Mpa after coating and baking and a method for manufacturing the steel sheet for cans are provided. The steel sheet for cans contains, on the basis of mass percent, C: more than 0.02% but 0.10% or less, Si: 0.10% or less, Mn: 1.5% or less, P: 0.20% or less, S: 0.20% or less, Al: 0.10% or less, N: 0.0120% to 0.0250%, dissolved N being 0.0100% or more, and a remainder of Fe and incidental impurities. A high-strength material can be obtained by maintaining the absolute quantity of dissolved N at a certain value or more and performing hardening by quench aging and strain aging, for example, in a printing process, a film lamination process, or a drying and baking process performed before can manufacturing. In the manufacture, hot rolling is performed at a slab extraction temperature of 1200° C. or more and a finish rolling temperature of (Ar3 transformation temperature—30)° C. or more, and coiling is performed at 650° C. or less.

Abstract: A method of producing a steel sheet useful for making cans. The method steps include hot-rolling a slab consisting of about 0.0005 to 0.01 wt % C, about 0.001 to 0.04 wt % N (the total of C and N is at least about 0.008 wt %), about 0.05 to 2.0 wt % Mn, about 0.005 wt % or less Al, about 0.01 wt % or less O at a finish rolling temperature within a temperature range of about the Ar.sub.3 point to about 950.degree. C., coiling the rolled material at a temperature range of about 400 to 600.degree. C., cold rolling the material, continuously annealing the material at a temperature higher than the recrystallization temperature, and then temper-rolling the material. The steel sheet exhibits good workability during can making and which can be formed into a can having high strength.

Abstract: A method of manufacturing a cold-rolled can steel sheet having less planar anisotropy and achieving good workability. Rough-rolling is first performed on a continuously-cast slab. The slab has a composition essentially consisting of: C: 0.004 wt % or lower; Mn: 0.05-0.5 wt %; P: 0.02 wt % or lower; Al: 0.005-0.07 wt %; N: 0.004 wt % or lower; and Nb: 0.001-0.018 wt %, the rest being Fe and unavoidable impurities. A resultant sheet bar is then subjected to hot rolling which is completed at a finishing rolling temperature at an Ar.sub.3 transformation point or higher. The resultant sheet bar is coiled at a temperature range from 450.degree.-700.degree. C. Subsequently, the resultant sheet bar undergoes primary cold rolling before continuous annealing, which is performed at a recrystallization temperature or higher, and secondary cold rolling. The primary and secondary cold rolling are respectively performed at reduction ratios satisfying the following conditions of:88%.gtoreq.CR.sub.1 %+0.36.times.CR.sub.2 .

Abstract: A method for manufacturing a canning steel sheet with non-aging property and superior workability uses, as a starting material, an ultra-low-carbon steel slab composed of from 0.0015% to 0.0100% by weight C, up to 0.20% by weight Si, from 0.10% to 1.20% by weight Mn, from 0.02% to 0.10% by weight Al, from 0.005% to 0.040% by weight P, up to 0.015% by weight S, up to 0.005% by weight N, and balance iron and unavoidable impurities. The manufacturing method includes hot rolling the steel, cold rolling the steel at a reduction ratio not less than 70% after pickling, and recrystallization annealing the steel by using a continuous annealing furnace in an atmosphere having a hydrogen content not less than 3% and a dew point not lower than -20.degree. C. at a temperature not lower than 730.degree. C. so that the content of remained C in the steel is kept less than 0.0015% by weight. At least one element selected from Nb, Ti and B may be added in predetermined amounts to the above composition.

Abstract: A method of manufacturing a small planar anisotropic high-strength can steel plate. Hot-rolling is first performed on a steel slab at an Ar.sub.3 transformation point or higher to obtain hot rolled steel strip. The slab has a composition which essentially consists of and which satisfies the conditions of: C.ltoreq.0.004%, Si.ltoreq.0.02%, Mn=0.5%-3%, P.ltoreq.0.02%, Al=0.02%-0.05%, 0.008%.ltoreq.N.ltoreq.0.024%, and the rest being Fe and unavoidable impurities, wherein the conditions have the relationship of:Al%/N%>2. Then, the resultant strip is cooled at a cooling rate of 10.degree. C./s or higher so as to reach a temperature of 650.degree. C. or lower. The resultant strip is further coiled at a temperature in a range of from 550.degree. C. to 400.degree. C. Cold-rolling is performed on the resultant strip at a reduction ratio of 82% or higher preceded by removing a scale to obtain cold rolled steel strip.