HIGH STRENGTH MEMBER AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a high strength member having improved toughness and ductility and also to provide its manufacturing method. SOLUTION: The high strength member can be obtained by heating a high strength steel sheet up to a temperature in an austenite region and then applying press forming and cooling in a die, and the high strength steel sheet has a composition containing 0.1 to 0.4% C, 0.1 to 2.0% Mo and 0.1 to 2.0% Cr and also has a structure containing precipitates composed of metal carbides of 0.01 to 5μm grain size in the steel. In the method for manufacturing the high strength member, the high strength steel sheet is heated up to a temperature in an austenite region by sandwiching both faces of the high strength steel sheet between induction heated steel materials and is then press formed and cooled in a die to obtain the desired high strength member. COPYRIGHT: (C)2008,JPO&INPIT