POSCO Holdings Inc.
ZINC-BASED PLATED STEEL SHEET HAVING EXCELLENT ROOM TEMPERATURE AGING RESISTANCE AND BAKE HARDENABILITY, AND METHOD FOR PRODUCING SAME

Abstract:

A zinc-based plated steel sheet having excellent room temperature aging resistance and bake hardenability includes a base steel sheet and a zinc-based plating layer formed on the surface of the base steel sheet, wherein the base steel sheet contains, in wt %, no more than 0.005% (excluding 0%) of C, 0.1-1.0% of Mn, no more than 0.3% (excluding 0%) of Si, 0.01-0.08% of P, no more than 0.01% of S, no more than 0.01% of N, 0.01-0.06% of sol.Al, 0.002-0.02% of Nb, and 0.001-0.004% (excluding 0.001%) of B, with the remainder comprising Fe and inevitable impurities, and CS in formula 1 below may satisfy the range of 0.0002-0.002%. In formula 1, [C] and [Nb] represent the contents (wt %) of C and Nb, respectively, in the base steel sheet. CS=[C]-(12/93)*[Nb] [Formula 1]