HIGH-STRENGTH COLD-ROLLED STEEL SHEET EXCELLENT IN COATING ADHESION, WORKABILITY AND HYDROGEN EMBRITTLEMENT RESISTANCE, AND STEEL COMPONENT FOR AUTOMOBILE

摘要

Disclosed is a cold-rolled steel sheet having a chemical composition satisfying, in mass%, C:0.06-0.6%, Si: 0.1-2%, Al: 0.01-3%, Si + Al: 1-4%, Mn: 1-6% and Si/Mn = 0.40. There are 10 or more Mn-Si complex oxides having an Mn/Si atomic ratio of not less than 0.5 and a length of 0.01-5 µm per 100 µm² of the steel sheet surface, and not more than 10% of the steel sheet surface is covered by oxides mainly containing Si.