STEEL SHEET FOR HOT PRESS FORMING HAVING EXCELLENT HEAT TREATMENT AND IMPACT PROPERTY, HOT PRESS PARTS MADE OF IT AND THE METHOD FOR MANUFACTURING THEREOF

摘要

Disclosed is a steel sheet that exhibits an ultra-high strength after hot press forming followed by rapid cooling, and an enhanced yield strength after painting. The steel sheet has a composition comprising 0.1% to 0.5% by weight of C, 0.01% to 1.0% by weight of Si, 0.5% to 4.0% by weight of Mn, 0.1 % by weight or less of P, 0.03% by weight or less of S, 0.1 % by weight of soluble Al, 0.01% to 0.1% by weight of N, 0.3% by weight or less of W, and the balance Fe and other inevitable impurities. Further disclosed are a hot-pressed part made of the steel sheet and a method for manufacturing the hot-pressed part. The hot-pressed part achieves a high increment in yield strength after heat treatment for painting while ensuring an ultra-high tensile strength. Furthermore, the hot-pressed part exhibits superior adhesion to a coatinglayer, good surface appearance and improved corrosion resistance after painting. WO2007064172A1