| Title |
Effects of Solution Treating Time on the Creep - Rupture Properties in Ni - Base Superalloy , Mar - M247LC |
| Authors |
나영상(Young Sang Na); 이종훈(Jong Hun Lee); 최승주(Seung Ju Choe); 김학민(Hak Min Kim) |
| Abstract |
Stress rupture behavior of Mar-M247LC alloy was investigated in the temperature range of 760℃-980℃. The amount of residual eutectic γ` was varied by controlling the solution treating time at 1260℃. As the solution treating time at 1260℃ was increased, the amount of residual eutectic γ` was reduced and the stress-rupture life was increased. Especially the increase of rupture lives are more pronounced in the 760℃/587MPa condition than in the 982℃/152MPa condition. In the 760℃/587MPa rupture is occured by both transgranular and intergranular mechanism. It was observed that the small grains were disappeared during solution treatment because of the reduced amount of residual eutectic γ` associated with the increased solution treating time, which was considered as one of the barriers for the migration of grain boundaries. The improved stress-rupture life was attributed to the disappearance of the isolated small grains as well as the reduction of the amount of residual eutectic γ` which acted as early crack initiation sites. |