Patent ID: 11420247

Abstract:
Disclosed is a hot-pressed member that can exhibit very high tensile strength after hot pressing of 1780 MPa or more, excellent delayed fracture resistance, and high cross tensile strength after resistance spot welding by properly adjusting its chemical composition and its microstructure such that a prior austenite average grain size is 8 μm or less, a volume fraction of martensite is 90% or more, and at least 10 cementite grains having a grain size of 0.05 μm or more are present on average per 200 μm2 of a cross section parallel to a thickness direction of the member, and such that at least 10 Ti-based precipitates having a grain size of less than 0.10 μm are present on average per 100 μm2 of the cross section parallel to the thickness direction of the member in a range of 100 μm in the thickness direction from a surface of the member.