Alloyed Hot Dip Galvanized Steel Sheet

Abstract: Provided is a high-strength plated steel sheet having high hydrogen embrittlement resistance. Provided is an alloyed hot-dip galvanized steel sheet including: a steel sheet that includes 0.05-0.40% C, 0.2-3.0% Si, 0.1-5.0% Mn, and 0.4-1.50% sol Al; and, on at least one surface of the steel sheet, an alloyed hot-dip galvanization layer that includes 5.0-15.0% Fe and 0.01-1.0% Al attached in the amount of 10-100 g/m2, wherein the alloyed hot-dip galvanized steel sheet has an internal oxidation layer including a grain boundary oxide on a surface layer of the steel sheet, and when a cross section of the surface layer of the steel sheet is observed, the ratio A of the length of the grain boundary oxide projected on the interface between the steel sheet and the alloyed hot-dip galvanization layer to the length of said interface is 50-100%, and the steel composition not including oxides includes a surface layer depletion layer that satisfies, in terms of mass%, the expressions Si = 0.6% and Al = 0.05% at a depth that is ½ the average depth of the internal oxidation layer calculated from a cross-sectional SEM image of the steel sheet.

Patent Information

Applicants

Inventors

Specification

Documents

Application Documents