ArcelorMittal S.A.
High-strength cold rolled steel sheet having high formability and a method of manufacturing thereof

Abstract:

A cold rolled steel sheet, the steel containing, in weight percentage, 0.19%.ltoreq.carbon.ltoreq.0.24%, 1.9%.ltoreq.manganese.ltoreq.2.2%, 1.4%.ltoreq.silicon.ltoreq.1.6%, 0.01%.ltoreq.aluminum.ltoreq.0.06%, 0.2%.ltoreq.chromium.ltoreq.0.5%, phosphorus.ltoreq.0.02%, sulfur.ltoreq.0.003%, the balance including iron and unavoidable impurities, the steel sheet having a microstructure containing 5% to 15% of tempered martensite, 10% to 15% of residual austenite, the balance containing bainite, bainite content being at least 70%, is described. Also described is a manufacturing method and with use of such grade for making vehicle parts.