Rust resistance and machinability satisfactory high Mn nonmagnetic steel

摘要

PURPOSE:To improve the rust resistance and machinability of a high Mn steel having a specified compsn. by adding specified amts. of P, S and Cr in combination. CONSTITUTION:This nonmagnetic high Mn steel consists of, by weight, 0.05-0.40% C, 0.05-0.70% Si, 15.0-25.0% Mn, 0.050-0.100% P, 0.010-0.050% S, =4.0% Ni, 15.5-20.0% Cr, 0.15-0.60% N, =0.01% O, =0.05% Al and the balance Fe or further contains 0.001-0.010% Ca, 0.7-4.0% Cu and/or 0.7-3.0% Mo and/or 0.005-1.0% each of one or more among V, Ti, Nb, W and Zr. In the steel, P improves the machinability but less than the lower limit amt. of P does not produce the satisfactory effect and more than the upper limit amt. of P deteriorates the corrosion resistance. The machinability is further improved by the synergism of S with P, but less than the lower limit amt. of S does not produce the satisfactory effect and more than the upper limit amt. of S deteriorates the rust resistance.