This paper describes an X-ray fractography for low-cycle fatigue of SUS 304 stainless steel at 873K in air under two test conditions. The first was the total strain range controlled test using triangular waves at a frequency of 0.1Hz and the second was the stress range controlled test using triangular and trapezoid waves at frequencies from 10-4Hz to 1Hz.
(1) The half-value breadth obtained from X-ray diffraction on the fracture surfaces of low-cycle fatigue at high temperature was well correlated with the strain range but not with frequency. The half-value breadth was also correlated well with the failure life of the material fractured transgranularly, but was not in the case of intergranular fracture.
(2) The particle size and microstrain obtained by Fourier analysis for X-ray profiles could be the good parameters for predicting low cycle fatigue life in both of the transgranular and intergranular fracture regimes.
