Being the alloy hot dip zincing steel sheet where alloy hot dip zincing layer was covered to the high intensity

摘要

PROBLEM TO BE SOLVED: To provide a high-strength galvannealed steel sheet excellent in plating adhesion and powdering resistance.;SOLUTION: The high-strength galvannealed steel sheet is manufactured by coating a base steel sheet with a galvannealed layer, wherein the base steel sheet has a chemical composition comprising, by mass, 0.1-0.3% C, ≤0.2% Si, 1.0-4.0% Mn, ≤0.1% P, ≤0.01% S, 0.01-3.0% Al and the balance Fe with unavoidable impurities. The base steel sheet has an average Al content (average Al concentration) of ≥1.5% in a boundary region where the amounts of Zn to Fe in the thickness direction locally satisfy the ratio [Zn]/[Fe] of 0.5-5.0.;COPYRIGHT: (C)2011,JPO&INPIT