HIGH-STRENGTH PLATED STEEL SHEET HAVING SUPERIOR PLATING PROPERTIES, WORKABILITY, AND DELAYED FRACTURE RESISTANCE, AND METHOD FOR PRODUCING SAME

摘要

A hot-dip galvanized steel sheet and an alloyed hot-dip galvanized steel sheet each having a tensile strength of 980 MPa or more and excellent in plating properties, workability including bending workability and hole expandability, delayed, fracture resistance, and shock absorption are provided. A high-strength plated steel sheet according to the present invention is a plated steel sheet having a plated layer on a surface of a base steel sheet, contains predetermined steel compositions, and includes, in order from a base steel sheet side of an interface between the base steel sheet and the plated layer: a soft layer having a Vickers hardness of 90% or less of a Vickers hardness of a t/4 portion of the base steel sheet, where t is a thickness of the base steel sheet, and a hard layer having a structure containing martensite and bainite as main components. The soft layer has an average depth D of 20 µm or more, an internal oxide layer has an average depth d of 4 µm or more and less than D.