HIGH-STRENGTH COLD-ROLLED STEEL SHEET WITH EXCELLENT WORKABILITY AND METHOD OF MANUFACTURING THE SAME, CAPABLE OF IMPROVING ELONGATION, STRETCH FLANGEABILITY AND BENDABILITY

摘要

PURPOSE: A high-strength cold-rolled steel sheet with excellent workability and a method of manufacturing the same are provided to ensure excellent workability and over 980MPa of tensile strength since elongation, stretch flangeability and bendability of a cold-rolled steel sheet are improved.;CONSTITUTION: A high-strength cold-rolled steel sheet with excellent workability, by mass%, contains C: 0.10 ~ 0.3%, Si: 1.0 ~ 3.0%, Mn: 1.5 ~ 3%, Al: 0.005 ~ 0.2% and satisfies P: 0.1% or less, S 0.05% or less. The steel sheet contains Fe and inevitable impurities. The metal organization of the steel sheet comprises bainite, residual austenite and tempered martensite. When the metallic organization is observed by a scanning electron microscope, the bainite consists of a composite organization of a high-temperature region of bainte and a low-temperature region of bainite.;COPYRIGHT KIPO 2011