两种组织的Ren80高温合金的蠕变裂纹扩展行为

CREEP CRACK PROPAGATION IN CONVENTIONAL CAST AND DIRECTIONALLY SOLIDIFIED SUPERALLOY RENE 80

研究了定向凝固和普通铸造的Ren80合金在1123K静载荷下的蠕变裂纹扩展行为结果表明,Ren80合金蠕变裂纹扩展速率,可用应力强度因子较好地关联定向凝固合金蠕变裂纹与扩展速率较低。

The creep crack propagation in superalloy Rene80 of two differentmicrostructures, i.e., equiaxed grain structure by conventional casting and columnar grain bydirectional solidification, was investigated under static load at 1123 K. The creep crackgrowth rate, dα/dt, seems to be correlated with the stress intensity factor, K. The creep crackgrowth rate in the directionally solidified alloy is lower than that in the conventional castalloy, owing to the elimination of transverse grain boundaries. The effect of microstructure oncreep crack propagation has also been discussed.