Measurement of three-dimensional geometry of creep void, and new method for residual life prediction by void volume ratio

蠕变是高温设备的失效模式之一。利用蠕变空洞为小空位的特点，通过统计分析估算剩余寿命。以前，使用二维分析的空隙。本研究将3D-EBSD方法与SEM图像相结合，发展了一种孔洞三维几何形状的测量方法。该方法能够对空洞进行三维分析。该方法适用于蠕变损伤的Chrome Mo钢。结果表明，孔隙体积比、几何形状随时间的变化以及含孔隙晶界与应力方向的关系。

Creep is one of the failure mode of high temperature equipment. Residual life is estimated by statistic analysis using feature of creep void that is small vacancy. Previously, the two dimensional analysis for void is used. In this research, method for measurement of three-dimensional geometry of void is developed by combining 3D-EBSD method and SEM images. The method enabled three-dimensional analysis of void. The method is applied to Chrome Molybdenum Steel that has been creep damaged. In the results, the void volume ratio, the variation of geometry by time and the relationship between grain boundary with void and stress direction are clarified.