HIGH-MN NONMAGNETIC STEEL FOR VERY LOW TEMPERATURE USE EXCELLENT IN ELECTRON BEAM WELDABILITY

摘要

PURPOSE:To obtain a high-Mn nonmagnetic steel for very low temp. use for large-sized superconducting magnet excellent in electron beam weldability by incorporating specific percentage of C, Si, Mn, P, S, O, Ni, Cr and N to Fe. CONSTITUTION:The high-Mn nonmagnetic steel consisting of, by weight, 0.01-0.15% C, 0.01-1.50% Si, 10-30% Mn, =0.03% P, =0.01% S, =0.0030% O, 0.5-1.5% Ni, 12-25% Cr, 0.10-0.28% N and the balance Fe with inevitable impurities and satisfying [(%Mn)-0.3(%Ni)+2.0(%Cr)]/(%N)X102=2.0 is prepared. This steel is excellent in electron beam weldability and has high strength and toughness at a joint at -269 deg.C and has superior magnetic properties as well, so that it is suitably used as large-sized superconducting magnet for nuclear fusion reactor, MHD generator equipment, etc.