CHARACTERISTIC OF CRACK GROWTH LIFE FOR W ADDED 9CR FERRITIC HEAT RESISTANT STEEL UNDER THE CONDITIONS OF HIGH TEMPERATURE CREEP-FATIGUE MULTIPLICATION BASED ON NON-EQUILIBRIUM SCIENCE

摘要

The W added 9Cr ferritic heat resistant steel ASME grade P92, developed as a boiler tube material, is used under the conditions of creep-fatigue multiplication. In this paper, using P92 steel, crack growth tests under the conditions of creep-fatigue multiplication were conducted and the effects of cycle-dependent and time-dependent mechanisms on the crack growth life t_f were investigated. Furthermore, on the basis of the concept of non-equilibrium science, the multiple effects of creep and fatigue on the crack growth life t_f were clarified.