Model of Grain Deformation Method for Evaluation of Creep Life in In-Service Components

Abstract

The creep life can be evaluated by the degree of grain deformation since the grains of Cr-Mo base material deform in the direction of stress. The grain deformation method using image-processing technique is developed for life assessment of in-service high temperature components. The new assessment model for the method is presented to apply to in-service components and is verified by interrupted creep test for ex-serviced material of 1Cr-0.5Mo steel. The proposed model, which is irrespective of stress direction, is to evaluate mean of the absolute deviation for the measured aspect ratios of the grains sections. [S0094-4289(00)00801-X]