| 摘要 |
PURPOSE:To manufacture a high Mn nonmagnetic steel having high strength and a high yield ratio by restricting the composition of a steel, hot rolling the steel and cooling it at once at a cooling rate between the air cooling rate and a specified cooling rate. CONSTITUTION:The composition of a steel is composed of, by weight, <1.5% C, <0.8% Si, [-9.26C(%)+19.03]-35% Mn, <0.25% N and the balance Fe with inevitable impurities. The composition may further contain three or less among <5% Cr, <0.5% V, <3% Mo, <0.2% Ti, <0.3% Ni and <0.01% Ca. The steel is heated to 1,000-1,250 deg.C, hot rolled at 700-1,000 deg.C and cooled at once at a cooling rate between the air cooling rate and 100 deg.C/sec. |
