Low-Cycle Fatigue Behavior of Reduced Activation Ferritic-Martensitic Steel at Elevated Temperatures

Changes in the low-cycle fatigue (LCF) behavior of reduced activation ferritic-martensitic (RAFM) steel containing trace amount of Zr—namely, Advanced Reduced Activation Alloy (ARAA) were presented in the temperature range of 573 to 873 K. The fatigue lifetime decreased significantly as the temperature increased from 573 to 823 K, but it was rather similar between 823 and 873 K, where the tensile properties deteriorated most rapidly. The decrease in lifetime at elevated temperatures is mainly due to the disappearance of the initial tempered martensitic structure during cycling resulting in rapid cyclic softening and local oxidation at surface slip bands which led to earlier crack initiation. The fatigue lifetime and cyclic softening behavior of ARAA were compared with those of the other conventional RAFM steels. Graphical Abstract