Model of grain deformation method for evaluation of creep life in in-service components

The creep life can be evaluated by the degree of grain deformation since th e grains of Cr-Mo base material deform in the direction of stress. The grai n deformation method using image-processing technique is developed for life assessment of in-service high temperature components. The new assessment m odel for the method is presented to apply to in-service components and is v erified by interrupted creep test for ex-serviced material of ICr-0.5Mo ste el. The proposed model, which is irrespective of stress direction, is to ev aluate mean of the absolute deviation for the measured aspect ratios of the grains sections.