1990 Volume 76 Issue 7 Pages 1187-1194
The high temperature creep resistance of as solution treated specimen of a Ni-30Cr alloy containing 0.04wt% carbon has been investigated by comparing with that of the specimen aged at 900°C for 1000 h, focusing on the difference in carbide morphology. Minimum creep rate of as solution treated specimen was two orders of magnitude less than that of the aged one under higher stress levels. In as solution treated specimen crept under higher stress levels, most of grain boundaries were covered with intergranular carbides and the region consisting of fine carbides precipitated on dislocations were formed along grain boundaries. Corresponding to the formation of this region, the marked reduction in minimum creep rate occurred. Carbide precipitation on dislocation during creep was attributed to the formation of the region with high dislocation density along the grain boundaries due to the high area fraction in grain boundaries covered by carbides.