POSCO Holdings Inc.
PLATED STEEL SHEET FOR HOT PRESS FORMING HAVING EXCELLENT IMPACT PROPERTY, HOT PRESS FORMED PART, AND MANUFACTURING METHOD THEREOF

Abstract:

Provided is a plated steel sheet for hot press forming, having an excellent impact property, including: a base steel sheet comprising, by wt %, 0.15-0.4% of C, 0.05-1.0% of Si, 0.6-3.0% of Mn, 0.001-0.05% of P, 0.0001-0.02% of S, 0.01-0.1% of Al, 0.001-0.02% of N, 0.001-0.01% of B, 0.01-0.5% of Cr, 0.01-0.05% of Ti, and the balance of Fe and inevitable impurities; and an Al--Si plated layer formed on the surface of the base steel sheet. A thickness of a carbon-depleted layer in a surface layer part of the base steel sheet is 5 .mu.m or less. The surface layer part means a region from the surface of the base steel sheet to a depth of 200 .mu.m, and the carbon-depleted layer means a region which the carbon content is 50% or less of an average carbon amount (C.sub.0) of the base steel sheet.