Abstract
In order to develop high efficient power plants (A-USC), it is essential to examine some mechanical properties for candidate high corrosion and heat-resistant steels. These materials, if employed, can reduce CO_2 emissions due to good performances in high temperatures and high pressure. Ferritic steel which has a low coefficient of thermal expansion are required to prevent thermal fatigue due to frequent start-stop operations. In this study, low cycle fatigue tests were conducted at 630 ℃ with a smooth bar specimens which are made from high Cr steel (P92), one of advanced heat-resistant steels. Initiation of creep fatigue crack was investigated with interrupted tests. In the case of conventional fatigue test, the crack initiation life is 1100 cycle act strain range of ΔEr_t=0.8%. Although the crack initiation life at the fatigue test with tensile holding is different from the triangular creep fatigue test, both the crack initiation life is 50% of the failure life.
