Study of Lead–bismuth Eutectic on Material Performance Degradation and Life Assessment for Modified 9Cr-1Mo Steel under Low Cycle Fatigue at High Temperatures

Lead-bismuth eutectic (LBE) serves as one of the efficient coolants in Generation IV nuclear reactors. Considering LBE degradation, the aims of the present work are to propose a fatigue life prediction model at material-level and to obtain a component-level fatigue assessment. The LBE degradation factors of temperatures, strain ranges and strain rates are incorporated into the proposed life prediction model. Afterwards, fatigue life design curves are correspondingly put forward. Furthermore, recommended fatigue life assessment procedures are established for engineering applications. Finally, a continuous process in "deformation-cracking-repassivation" of oxide films is discussed to reveal oxidation-sensitive LBE degradation mechanism.