STEEL SHEET FOR HOT STAMPING USE, METHOD OF PRODUCTION OF SAME, AND METHOD OF PRODUCTION OF HIGH STRENGTH PART

摘要

The present invention addresses the problem of providing steel sheets for hot stamping which have excellent post-hot-stamping part strength and resistance to delayed fracture. These steel sheets contain, in percentages by mass, 0.05 to 0.40% C, not more than 0.02% Si, 0.1 to 3% Mn, not more than 0.02% S, not more than 0.03% P, not more than 0.005% Al, not more than 0.01% Ti, not more than 0.01% N, a total of 0.005 to 1% of Cr and/or Mo, and 0.003 to 0.03% O. The remainder comprises chemical components of Fe and unavoidable impurities. The problem is resolved by generating Fe-Mn complex oxides with an average diameter of 0.1 to 15 µm in the steel sheets, and trapping hydrogen between the complex oxides and the interface of the steel, which is the matrix, and in gaps around the complex oxides.