C: 0.04%-0.10% Si: 0.30%-0.60% Mn: 1.50% max P: 0.035% max S: 0.015% max Cr: 15.5%-17.5% Ni: 15.5%-17.5% Nb: 10×C-1.20% W: 2.50%-3.50% N: 0.06%-0.14%