Fatigue crack propagation behavior of K40S cobalt-base superalloy at elevated temperature
来源期刊：中国有色金属学报(英文版)2003年第1期
论文作者：杨富民 孙晓峰 管恒荣 邓午立 刘芳 胡壮麒
文章页码：50 - 54
Key words：cobalt-base superalloy; fatigue crack propagation; fatigue threshold; ductility
Abstract: Fatigue crack propagation behavior of K40S cobalt-base superalloy under ambient atmosphere at 700℃ and 900℃ was investigated. The detailed fatigue crack propagation and fracture mechanism under the alternating loads were studied. The results show that, there is a defined threshold for K40S alloy at elevated temperatures. The fatigue threshold is 23.9MPa·m1/2 at 700℃ and 12MPa·m1/2 at 900℃. The significant decrease of the threshold with increasing temperature is associated with the oxidation induced embrittlement at crack tip. Observation on the fatigue fracture surfaces indicates a ductile fracture mechanism related to the fatigue crack growth.
