Document Type and Number:
Japanese Patent JPWO2023167318
Kind Code:
A1
Abstract:
Provided is a steel material that can reduce the hydrogen embrittlement susceptibility of bolts. This steel material contains, in mass%, 0.30-0.50% of C, 0.01-0.30% of Si, 0.10-1.50% of Mn, 0.030% or less of P, 0.030% or less of S, 0.01-0.80% of Cr, at least 0.70% and less than 1.50% of Mo, 0.01-0.50% of V, 0.005-0.100% of Al, and 0.0010-0.0300% of N, with the remainder comprising Fe and inevitable impurities, wherein the area percentage of hard phases is at least 90%, the Vickers hardness is 220-400 HV, the number density of cementite in the hard phases is at least 4.0/μm2, the number percentage of cementite having an area of 0.0005-0.0100 μm2 among a plurality of cementite phases in the hard phases is at least 50.0%, and the sample standard deviation of the areas of the plurality of cementite phases in the hard phases is 0.070 μm2 or less.
Application Number:
JP2023532406A
Publication Date:
September 07, 2023
Filing Date:
March 03, 2023
Export Citation:
