ＳＵＳ３０４鋼の高温におけるクリープ・疲労損傷量評価と余寿命推定に関する研究 Ｘ線によるクリープ・疲労損傷評価の検討

Abstract

This paper describes damage evaluation and estimation of remaining life of SUS 304 stainless steel in creep, low-cycle fatigue and creep-fatigue at 873K in air. Creep, fatigue and creep-fatigue damage curves were drawn by the method proposed by D.A. Woodford and the relations between these damages and non-destructive parameters, i.e., microvickers hardness and quantities obtained from X-ray diffraction, were discussed. From these tests, the following conclusions were obtained.(1) Constant damage lines in the diagram of remaining lives in creep and fatigue could be drawn by changing load levels during the tests. Constant damage lines in creep-fatigue were also made by a linear damage rule using both static creep and fatigue damage curves, which agree well with the experimental data in creep-fatigue.(2) Microvickers hardness and half-value breadth in X-ray diffraction are appropriate parameters to evaluate creep damage but are not proper to evaluate fatigue damage. Particle size and microstrain obtained by X-ray profile analysis are good parameters to evaluate both creep and fatigue damages.