THIN-STRIP CAST PIECE OF AUSTENITIC STAINLESS STEEL, THIN-STRIP COLD-ROLLED STEEL PLATE AND METHOD OF MANUFACTURING THE SAME

摘要

This invention relates to a cast piece of austenitic stainless steel produced on a double-roll continuous casting machine, a cold-rolled steel plate, and a method of manufacturing them, and aims at providing a thin austenitic stainless steel plate free from the occurrence of surface roughening during cold molding operation. A thin-strip cast piece is produced by a double roll continuous casting method with the degree of segregation of Ni, which is defined by the following equation (1), at the portion of the cast piece which is in the vicinity of the center of a cross section thereof regulated to not lower than 0.9, and the components of the cast piece are regulated so that delta -Fecal.(%) defined by the following equation (2) is not less than 6, the resultant cast piece being subjected to cold rolling once or twice to obtain a steel plate. According to this method, the casting is done with a drum pressing force per unit length of 3-25 Kg/mm applied in the widthwise direction of the cooling drum on a kissing point. Degree of segregation of Ni = Average quantity (%) of Ni a segregated portion/Aver age quantity (%) of Ni in a cast piece (1) delta Fecal. (%) = 3(Cr + 1.5Si + Mo + 0.5Nb)-2.8(Ni + 0.5Cu + 0.5Mn + 30C + 30N) - 19.8 (wherein the quantity of components is expressed by mass %) (2).