Fatigue crack growth rate of a low carbon microalloyed steel for high temperatures

The influence of temperature on the fatigue crack growth parameter, was analyzed by testing chromium-molybdenum steel of the new generation additionally alloyed with vanadium, designed for high temperatures application. The paper presents a comparison of the fatigue threshold value ΔKth and the fatigue crack growth rate da/dN of the specimens taken from the pipe made of virgin steel, tested at room (RT) and operating (HT) temperatures of 540 °C. The influence of the location of the notch and crack initiation, as well as the test temperature, have a decisive effect on the fatigue threshold values ΔKth of the chromium-molybdenum alloyed steel of the new generation additionally alloyed with vanadium for high temperatures application.