METHOD FOR MANUFACTURING HIGH-STRENGTH FORMED AND QUENCHED BODY SUPERIOR IN CORROSION RESISTANCE AND FATIGUE RESISTANCE, AND MANUFACTURING FACILITY THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-strength formed and quenched body superior in corrosion resistance and fatigue resistance from a galvanized steel material, which has corrosion resistance after having been quenched equal to or better than that of a cold-formed article, and to provide a facility therefor. SOLUTION: The galvanized steel material is provided with a galvanized layer containing either one or both of Al and Si in an amount of 0.15 mass% or more. The method for manufacturing the formed and quenched body comprises the steps of: heating the galvanized steel material to 800°C to 950°C in an oxidative atmosphere containing oxygen of 0.1 vol.% or more in a heating facility 1; then cooling it to 730°C to 500°C within 60 sec in a quenching facility 2; then forming it in a hot stamping facility 3; and quenching it. Thus formed and quenched body has a layer of 30 g/m2or more formed on the surface of the steel material, which contains Zn as a main component and 30 mass% or less Fe. COPYRIGHT: (C)2007,JPO&INPIT