Abstract: This invention aims at producing a cold rolled thin sheet having excellent surface quality from a cast strip of a Cr--Ni type stainless steel cast strip by a thin casting method. The production method of the invention comprises the steps of continuously casting a Cr--Ni type stainless steel to a cast strip having a thickness of not greater than 10 mm by using a continuous casting machine the cast mold wall surface of which moves in synchronism with the cast strip; hot rolling the resulting cast strip at a temperature within the range of 900 to 1,200.degree. C. at a reduction ratio of 10 to 50%; carrying out, subsequently, heat-treatment at a temperature within the range of 1,200 to 900.degree. C. for at least 5 seconds; coiling the hot rolled cast strip at a temperature not higher than 600.degree. C.; descaling the rolled cast strip; cold rolling the cast strip; conducting annealing, pickling or bright annealing; and conducting skin pass rolling, whenever necessary.

Abstract: An apparatus for the production of a stainless steel strip comprising the following devices provided in sequence: a twin-drum continuous casting machine; an atmosphere control cover having in its interior a bridle roll or a pinch roll; a hot-rolling machine; a heat-treating furnace comprising direct fire burners connected to header pipes juxtaposed to one another in the widthwise direction of the furnace over the longitudinal direction of the furnace; a cooler; and a coiler.

Abstract: An austenitic stainless steel sheet is produced by a twin-roll synchronous continuous casting process wherein the sheet has a Ni segregation ratio in the vicinity of its center section of 0.90 or more and .delta.Fe.sub.cal. (mass %) is 6 mass % or more. Ni segregation ratio is defined by the formula: {average Ni content of the segregated portion (%) }/{average Ni content of the cast sheet (%)}; where Ni content is expressed in % by mass. .delta.-Fe.sub.cal. (mass %) is defined by the formula: 3(Cr+1.5 Si+Mo+0.5 Nb)-2.8(Ni+0.5 Cu+0.5 Mn+30 C+30 N)-19.8; wherein the chemical elements are given in % by mass.

Abstract: This invention relates to a austenitic stainless steel thin sheet devoid of work-surface roughening, produced by a continuous casting method of a strip comprising a composition which contains not greater than 0.09% of C+N and has an Md.sub.30 of 30.degree. to 60.degree. C., and in which colonies A comprising {112}<111>, etc., and colonies B comprising {110}<111>, etc., exist in a uniform mixture in the steel sheet. As to colony dimensions, d.sub.RD (A) and d.sub.RD (B) are not greater than 300 .mu.m and d.sub.TD (A) and d.sub.TD (B) are not greater than 200 .mu.m. Solidification cooling is carried out at a cooling rate of at least 100.degree. C./sec, and cooling is carried out to 1,200.degree. C. at a rate of 50.degree. C./sec after solidification. Cold rolling is effected by twice cold rolling with interposed intermediate annealing. In this way, there can be obtained a austenitic strip cast stainless steel sheet not causing work-surface roughening.

Abstract: A process for producing a thin sheet of a Cr-Ni-based stainless steel having excellent surface quality and workability is produced by continuously casting a stainless steel represented by 18%Cr-8%Ni steel by means of a continuous casting machine having a mold wall surface that moves in synchronization with a cast strip, effecting rapid solidification at a cooling rate of 100.degree. C./sec or more into a cast strip having a thickness of 10 mm or less; after solidification thereof, initiating cooling of the cast strip from a high temperature at a rate of 100.degree. C./sec or more to 1250.degree. C. and preventing the occurrence of recuperation; holding the cooled cast strip in a temperature range of from over 900 to 1250.degree. C. exclusive for 5 sec to 2 min; and cooling and coiling the cast strip and subjecting the cast strip to annealing, pickling, cold rolling and annealing.

Abstract: A process for manufacturing a thin sheet of a Cr-Ni-base stainless steel having an excellent surface quality and material quality, which comprises casting a cast strip having a thickness of 6 mm or less from a Cr-Ni-base stainless steel including 18% Cr-8% Ni steel by a continuous casting wherein a casting mold is moved synchronously with the cast strip, and subjecting the cast strip to cold rolling to form a thin sheet product, wherein the cast strip immediately after the casting is coiled at a temperature of 800.degree. to 1200.degree. C. and subjected to cold rolling and final annealing to form a thin sheet product.

Abstract: Disclosed is a process for the producing coldrolled strips and sheets of austenitic stainless steel, which comprises preparing a cast strip having a thickness not larger than 10 mm, which is composed of an austenitic stainless steel, by a continuous casting machine, in which the wall surface of a casting mold moves synchronously with the cast strip, and cold rolling the cast strip by a hard rolls having a surface hardness not lower than the Vickers hardness of 600. A preferred embodiment of the present invention is characterized in that crystal grains of the cast strip are made finer by cooling the cast strip at a cooling rate of at least 50.degree. C./sec in the temperature range of from the temperature for initiation of solidification of the cast strip to 1200.degree. C. and the cast strip is then coldrolled by the hard rolls, another preferred embodiment of the present invention is characterized in that the hard rolls are composed of a material having a Young's modulus of at least 30000 kgf/mm.sup.

Abstract: A process for producing a cold-rolled strip or sheet of an austenitic stainless steel, comprising the steps of: casting a melt of an austenitic stainless steel into a cast strip in the form of a thin strip having a thickness of 10 mm or less by using a continuous caster in which a casting-mold wall is moved synchronously with the cast strip; cold-rolling the cast strip to form a cold-rolled strip; final annealing the cold-rolled strip; and skin-pass-rolling the annealed strip at an elongation of from 0.5 to 2.5%.

Abstract: A process in which a cast strip of Cr-Ni type stainless steel having a thickness close to a product thickness is prepared by the synchronous continuous casting. By subjecting the cast strip just below the casting machine to rapid cooling in the high-temperature region, hot-working or cold-working the cast strip and subjecting the cast strip to annealing or the like, .gamma. grains in the cast strip are made finer, and by carrying out cooling in the low-temperature region of temperatures lower than 900.degree. C., precipitation of Cr carbide in the grain boundary is prevented. Thus, occurrence of roping or uneven gloss on the surface of the stainless steel sheet is controlled.