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形式之一。利用蠕变孔洞小的特点，通过统计分析估计了蠕变孔洞的剩余寿命。在此之前，空洞的二维分析是常用的。本研究将3D-EBSD方法与SEM图像相结合，提出了一种测量孔隙三维几何形状的方法。该方法实现了对空洞的三维分析。将该方法应用于蠕变损伤的铬钼钢。研究结果阐明了孔洞体积比、孔洞几何形状随时间的变化以及晶界与孔洞和应力方向的关系。

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.