| 摘要 |
PURPOSE:To manufacture an austenitic stainless steel plate having high toughness as well as high strength at very low temp. by adding specific elements to an Ni-Cr-Mn low carbon steel and carrying out hot rolling and heat treatment under specific conditions. CONSTITUTION:The steel has a composition containing, by weight, 0.01-0.15% C, 0.01-2.00% Si, 0.5-16.0% Mn, <0.03% P, <0.01% S, 8.0-20.0% Ni, 12.0-20.0% Cr, 0.07-0.22% N, and at least one kind among 0.01-0.50% of Nb, V, and Ti and further containing, if necessary, 0.01-2.00% in total, of Cu and/or W or 0.001-0.10% of 1 or >=2 elements among Al, Ca, Ce, and Zn or 0.01-3.00% Mo independently or in combination. The above steel is subjected to hot rolling, finish rolling at 850-1,050 deg.C, isothermal holding to >=800 deg.C, air cooling, and then water cooling which is started at >=800 deg.C and continued down to >=500 deg.C. In this way, the steel plate of austenite grain size No.3.0-9.0 having high toughness as well as high yield strength at a temp. as low as -269 deg.C can be manufactured. |
