3D/4D Evaluation for Creep Damage Behavior in Mod.9Cr-1Mo Steel with X - ray Micro-tomography3D/4D Evaluation for Creep Damage Behavior in Mod.9Cr-1Mo Steel with X - ray Micro-tomography

Abstract

This study is concerned with observation and evaluation of the creep damage progress in the fine-grained heat affected zone (HAZ) of modified 9Cr-1Mo steels under multi-axial stress conditions. Creep rupture and interrupted tests have been carried out using a miniature creep test specimen. X-ray micro-tomography at SPring-8 has been applied to observe the creep damage process. Quantitative evaluation has been performed to identify the nucleation and growth of the creep voids. The increasing tendency of the void number density in the vicinity of notch root was observed by in situ quantitative analysis. Furthermore, macroscopic stress has been calculated in order to evaluate its correlation with the development of creep damage.