Abstract: A flaw detecting method and apparatus for continuously testing a strip that is continuously carried through a liquid includes features for reducing air bubble generation in a liquid. The apparatus includes a liquid, carrying rolls for passage of the strip through the liquid, and ultrasonic testing probes arranged in the liquid for testing the strip. A carrying roll in contact with the liquid is fully immersed. Air bubble generation is inhibited to improve the testing reliability by at least one of (a) shielding the liquid dropping from the portion of the strip leaving the liquid, (b) reducing the dropping force of the liquid onto the liquid surface by inclining the strip, (c) installing the fully immersed carrying roll at a depth of at least 5 mm in the liquid, and (d) using a carrying speed of less than about 200 m/min. Upon manufacturing steel strips, testing is carried out in the stage of hot-rolled steel sheet, or, preferably, in pickling equipment.

Abstract: The invention provides a can steel sheet having satisfactory surface appearance and having workability, appearance property after working and high yield that can meet demands on complicated can forming, and a manufacturing process thereof. To be more specific, according to the invention, a slab having a composition containing, in weight %, C: more than 0.005% and equal to or less than 0.1%, Mn: 0.05-1.0% is subjected to hot-rolling at a finishing temperature of 800 to 1000° C., to coiling at 500 to 750° C., to cold-rolling, followed by continuous annealing at a recrystallization temperature or higher and 800° C. or lower, and then to box annealing at a temperature higher than 500° C. and equal to or lower than 600° C. for 1 hr or longer. The steel sheet has preferably a structure containing ferrite as a principle phase and having a mean grain diameter of 10 &mgr;m or less and further containing 0.1-1% by weight of pearlite grains each having a grain diameter of 0.5-3 &mgr;m.

Abstract: At least both ends of a sheet bar in the length direction, which is obtained by roughly rolling a steel slab including 0.1 wt % or less of C, 0.5 wt % or less of Si, 1.0 wt % or less of Mn, 0.1 wt % or less of P, 0.05 wt % or less of S, 0.20 wt % or less of Al, and 0.015 wt % or less of N, are heated so that the temperature at both ends of the sheet bar in the length direction is 15° C. or more higher than the temperature of the remainder of the sheet bar. The rolling finish temperature is Ar3+20° C. to Ar3+100° C. in both end portions of the sheet bar in the length direction, and Ar3+10° C. to Ar3+60° C. in the remainder, and the rolling finish temperature in the both end portions in the length direction is 10° C. or more higher than that of the remainder, so that a steel strip after cold rolling and annealing has r values within ±0.3 of the average r value, and &Dgr;r within ±0.

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 steel slab is rough-rolled into a sheet bar and butt-joined onto a preceding sheet bar and a widthwise end portion of the sheet bar is heated by means of an edge heater and then subjected to a continuous finish rolling through pair-cross rolls rolling on at least 3 stands to provide a hot rolled steel strip having a width of not less than 950 mm, a thickness of 0.5-2 mm and a crown within .+-.40 .mu.m, and the hot rolled steel strip is subjected to cold rolling, continuous annealing, temper rolling and, if necessary, plating treatment on the surface of the cold rolled steel strip, whereby there is obtained a steel sheet having an average thickness of not more than 0.20 mm and a width of not less than 950 mm, a thickness variation quantity in a widthwise direction is within .+-.4% of the average thickness in a region corresponding to not less than 95% of the width of the steel sheet as cold rolled and a hardness (HR30T) variation in the widthwise direction is within .+-.3 of an average hardness.

Abstract: A method is provided for making a steel sheet suitable as a can material. The method includesa step for hot rolling a steel slab to a strip having a thickness of less than about 1.2 mm,a step for coiling the strip into a coil at a temperature range between about 600.degree. and 750.degree. C.,a step for pickling the coil with an acid, anda step for cold rolling the coil at a rolling reduction rate of about 50 to 90 percent, wherein the steel slab containsabout 0.0020 weight percent or less of carbon,about 0.020 weight percent or less of silicon,about 0.50 weight percent or less of manganese,about 0.020 weight percent or less of phosphorus,about 0.010 weight percent or less of sulfur,about 0.150 weight percent or less of aluminum,about 0.0050 weight percent or less of nitrogen, andthe balance iron and incidental impurities.A steel sheet suitable as a can material is also provided by this method.

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: There is provided an ultra-thin and high strength three-piece can-making plated steel sheet which is excellent in weldability and flange forming processibility containing C .ltoreq. about 0.004 wt %, Si.ltoreq. about 0.03 wt %, Mn: about 0.05-0.6 wt %, P.ltoreq. about 0.02 wt %, S.ltoreq. about 0.02 wt %, N.ltoreq. about 0.01 wt % Al: about 0.005-0.1 wt %, Nb: about 0.001-0.1 wt % and the balance of inevitable impurities. The steel sheet has a maximum recrystallization grain size of 30 .mu.m or less and a ratio of area of 50% or more which is occupied by recrystallization grains of about 5-25 .mu.m.

Abstract: A raw plated steel sheet for can comprises recrystallized particles containing approximately C<0,004%, Si<0.03%, Mn:0.05-0.6%, P<0.02%, S<0.02%, N<0.01%, Al:0.005-0.1%, Nb:0,001-0.1%, B:0.0001-0.005% in weight. The maximum diameter of a particle is less than about 30 .mu.m, and an area ratio of particles ranging about 5-25 .mu.m being more than about 50%. Such a steel sheet has excellent processing characteristics and good uniformity in product quality.

Abstract: An uneven patterned metal strip or plate is formed with an uneven pattern as a surface decorative pattern. The pattern is constituted of one or more pattern unit containing a plurality of uneven dot. Each of the uneven dots has a size D. The uneven dots are arranged in a predetermined density to have given ratio .eta. of occupying area versus plane area in said pattern unit. The size D and area ratio .eta. being in a range of:10.ltoreq.D.ltoreq.300 (.mu.m)30.ltoreq..eta..ltoreq.100 (%)and the size of said pattern unit has minimum length of 1 mm.

Abstract: A process for fusing a steel slab in a longitudinal direction thereof is disclosed, wherein when the steel slab is fused in the longitudinal direction at more than 500.degree. C. and at a speed of more than 300 mm/min., a surface portion of the slab including at least a lower portion of a longitudinally fused surface portion thereof is mechanically removed by cutting or grinding.

Abstract: Disclosed herein is a method of manufacturing a base steel sheet, which method comprises combined steps of: not rolling a steel slab containing not more than 0.0070% by weight of C (hereinafter referred to briefly as "%"), not more than 0.1% of Si, not more than 0.5% of Mn, 0.010 to 0.080% of Al, not more than 0.0050% of N, not more than 0.030% of S provided that the ratio of Mn/S is not less than 10, and not more than 0.030% of P while the hot rolling being terminated at a finish temperature of not less than 800.degree. C.; cold rolling thus obtained hot rolled steel sheet in an ordinary manner; continuously annealing the cold rolled steel sheet in which heating is done up to a temperature from a recrystallization temperature to 800.degree. C.

Abstract: A method of manufacturing T-3 grade low temper blackplates having an excellent corrosion resistance by a continuous annealing process. In this method, after a continuously cast slab of low carbon aluminum killed steel consisting of 0.02-0.09% of C, not more than 0.04% of Si, 0.15-0.40% of Mn, 0.003-0.02% of soluble Al, not more than 0.0040% in total of N and the balance of Fe and inevitable impurities is subjected to hot rolling, coiled at a temperature of less than 580.degree. C., pickled and subjected to cold rolling, the resulting cold-rolled strip is subjected to such a continuous annealing that the strip is maintained at a temperature above 680.degree. C. for at least 20 seconds, quenched up to a temperature below 500.degree. C. at a cooling rate of 10.degree.-500.degree. C./sec, maintained at a temperature of 350.degree.-500.degree. C. for at least 20 seconds and cooled to room temperature.

Abstract: Steel sheets having an excellent enamelability are produced by adjusting the carbon, silicon, manganese, aluminum, oxygen and boron contents in a molten steel to be not more than 0.020% of carbon, not more than 0.03% of silicon, not more than 0.50% of manganese, not more than 0.010% of aluminum, nor more than 0.050% of oxygen, boron within a range of 0.003-0.020% being in such an amount B(%).times.0(%) of more than 1.times.10.sup..sup.-5 and the remainder being inevitable impurities and iron, and hot rolling the resulting steel, cold rolling the steel and subjecting to a recrystallization annealing in a conventional manner.