HOT-ROLLED STEEL SHEET AND PRODUCTION METHOD THEREFOR

摘要

This hot-rolled steel sheet contains 0.02%-0.5% by mass C and has a total Si and Al content of 1.0%-4.0% by mass. The average pole density for a group of {100}<011>-{223}<110> orientations is 1.0-6.5 and the pole density for the {332}<113> crystal orientation is 1.0-5Ø The microstructure, by area ratio, contains 2%-30% residual austenite, 20%-50% ferrite, and 10%-60% bainite. The Lankford value (rC) in the direction perpendicular to the rolling direction is 0.70-1.10 and the Lankford value (r30) in a direction at 30° to the rolling direction is 0.70-1.10.