MANUFACTURE OF STEEL SHEET FOR WORKING HAVING SUPERIOR RIDGING RESISTANCE AND SUITABILITY TO CHEMICAL CONVERSION TREATMENT

摘要

PURPOSE:To obtain the titled steel sheet having satisfactory workability in shortened stages including no cold rolling stage by specifying rolling conditions and coiling temp. in a stage for rolling a low carbon steel to a prescribed thick ness and by subjecting the resulting steel strip to recrystallization annealing. CONSTITUTION:In a stage for rolling a low carbon steel to a prescribed thick ness, rolling is carried out at 800-300 deg.C and >=300 s<-1> rate of strain in at least one pass and the rolling is followed by coiling at <=400 deg.C. The resulting steel strip is subjected to recrystallization annealing. Thus, a steel sheet having supe rior ridging resistance and suitability to chemical conversion treatment as well as high ductility and a high r-value is obtd. by warm rolling at such a high rate of strain without carrying out conventional cold rolling.