HIGH-STRENGTH COLD ROLLED STEEL SHEET

摘要

PROBLEM TO BE SOLVED: To provide a high-strength cold rolled steel sheet free from the occurrence of 'bare spots' at hot dipping and 'nonuniform alloying' with alloying after plating and having excellent hot-dip platability and alloying ability after plating by devising the base material of a steel sheet. SOLUTION: The high-strength cold rolled steel sheet has oxides effective for the improvement of the above hot-dip platability, etc., in the grain boundary and/or crystal grain of the surface layer of the high-strength cold rolled steel sheet containing 0.1 to 3.0 wt.% Si.