| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for fining the crystal grains of a nitrogen-added Co-Cr-Mo alloy by which, in a nitrogen-containing Co-Cr-Mo alloy, a starting structure before hot working is controlled into a fine nitride-containing structure using heat treatment, hot working is performed at 930 to 1,030°C at which fine nitride is not vanished during the hot working to suppress the growth of recrystallized grains, and super fine grains of≤1μm can be formed. SOLUTION: Co-Cr-Mo based alloy containing, by weight, 26 to 35% Cr, 2 to 6% Mo, 0 to 0.2% Ni, 0.1 to 0.3% N and 0.01 to 0.20% C, and the balance Co is subjected to solution treatment, is then held at≤850°C for a fixed time or above to form a mixed phase structure of anεphase and nitride. With the mixed structure as the starting structure in hot working, the alloy is heated at 930 to 1,030°C at which the fine nitride is not vanished during hot working, and immediately after being heated or after held heated for a short period of time, the alloy is subjected to hot working to obtain super fine crystal grains of≤1μm. COPYRIGHT: (C)2011,JPO&INPIT |
