HIGH HARDNESS NON-MAGNETIC STEEL WITH REDUCED HYDROGEN EMBRITTLEMENT SUSCEPTIBILITY

摘要

To provide a steel that is inexpensive and has excellent hydrogen embrittlement resistance, tensile characteristics and corrosion resistance, by adjustments to the amount of addition of chemical components and the composition balance.SOLUTION: The present invention provides a high hardness non-magnetic steel with reduced hydrogen embrittlement susceptibility, which has, in mass%, C: 0.15-0.80%, Si: 0.15-0.80%, Mn: 2.0-10.0%, P: 0.050% or less, S: 0.030% or less, Ni: 8.0-20.0%, Cr: 8.0-18.0%, Mo: 0.05-0.50%, Cu: 0.20-5.00%, V: 0.50-3.00%, Al: 0.001-1.000%, N: 0.015-0.100%, with the balance being Fe and unavoidable impurities, and satisfying V/{4([C]+[N])}=0.5-1.0, {16([C]+[N])-3[V]}/([Cr]+0.9[Ni]-16[N])=0.10-0.30, 551-462([C]+[N]-0.07[V])-9.2[Si]-8.1[Mn]-13.7[Cr]-29([Ni]+[Cu])-18.5[Mo]≤-100, 2.3[Ni]+3.0[Mo]+5.0[Al]+5.6[Cu]-[Cr]-[Si]-1.2[Mn]≥18.5, wherein the number of V(C, N) deposits of 50 nm or less dispersed per 3.5×10μmis 50 or more.SELECTED DRAWING: None