抄録
The present paper describes a study on the effect of compressive strain holding on the high-temperature strength of Modified 9Cr-1Mo steel, a candidate steel for steam generator in a Japanese demonstrative fast breeder reactor, FBR. As usually known, the high-temperature fatigue strength of the Modified 9Cr-1Mo steel was significantly reduced by compressive strain holding. According to our observation by a scanning electron microscope, SEM, on the main-crack surface of the specimens failed under compressive strain holding, striations were clearly observed under compressive strain holding in air and tearing dimples in vacuum. It was guessed that compressive strain holding conditions gave a greater energy measure of fatigue damage to the specimens compared with no-holding conditions and this resulted in the reduction of the high temperature fatigue strength under compressive strain holding conditions.
