A method for manufacturing a hot-pressed member, a steel sheet for hot-pressing, and a method for manufacturing a hot-pressed member

摘要

A hot-pressed member excellent in press-in peel strength is provided. The tensile strength of the hot-pressed member is 1780 MPa or more. 10-point average roughness Rzjis of the surface of a plating layer is 25 micrometers or less. The steel sheet is, in mass%, C: 0.25% or more and less than 0.50%, Si: 1.5% or less, Mn: 1.1% or more and 2.4% or less, P: 0.05% or less, S: 0.005% or less, Al: 0.01% or more and 0.50% Hereinafter, N: 0.010% or less, Sb: 0.001% or more and 0.020% or less, Nb: 0.005% or more and 0.15% or less, and Ti: 0.005% or more and 0.15% or less, the remainder being Fe and unavoidable impurities. Within 50 µm in the sheet thickness direction from the surface of the steel sheet excluding the plating layer, the average grain size of prior austenite is 7 µm or less, and the volume ratio of martensite is 90% or more.