Interaction between High Temperature Fatigue and Creep of 1Cr18Ni9Ti Steel at Different Temperatures

In order to study the interaction between high temperature fatigue and creep at different temperatures, static creep and fatigue-creep tests were carried out on 1Cr18Ni9Ti steel at 600, 625, 650, 675 ℃ and 700 ℃, respectively. Creep life and high temperature fatigue-creep life were obtained by experiments, and high temperature fatigue life at different temperature was got by numerical simulation. And then, based on the above-mentioned data, creep damage and high temperature fatigue damage were calculated, the interaction coefficients between high temperature fatigue and creep at different temperature were obtained based on life prediction formula with interaction coefficient. At last, the effect of temperature on interaction coefficient was studied. The results indicate that when the temperature was below 625 ℃, the coefficient was negative and it was positive when temperature was above 625 ℃. Interaction curve bended to creep direction with the increase of temperature.