| 摘要 |
PURPOSE:To improve corrosion resistance and mechanical properties such as strength and toughness by specifying the relation between a heat treatment temp. and cooling rate in the stage of subjecting a two-phase stainless steel to a soln. heat treatment. CONSTITUTION:The soln. heat treatment of the austenite-ferrite two-phase stainless steel is executed under the conditions within the region enclosed by the six plot points at the coordinates where on axis indicates the heat treatment temp. and the other axis indicates cooling rate deg.C/sec. The heat treatment temp. is made 950-1,200 deg.C and the cooling rate is made 0.5-200 deg.C/sec. The plot points are 1,200 deg.C-0.5 deg.C/sec, 1,200 deg.C-1 deg.C/sec, 1,100 deg.C-25 deg.C/sec, 1,100 deg.C-200 deg.C/sec, 950 deg.C-0.5 deg.C/sec, 950 deg.C-200 deg.C/sec. The resistances to pitting, crevice corrosion, intergranular corrosion, stress corrosion cracking, etc., are improved by the above-mentioned soln. heat treatment. |
