Abstract
This study discusses creep-fatigue life of type F82H steel used in a blanket structure of a DEMO fusion reactor under uniaxial and multiaxial loadings at 823K. Strain controlled creep-fatigue tests were carried out using a hollow cylinder specimen. Three kinds of loading paths were employed; they were push-pull straining, reversed torsion straining and circular straining. The former two were proportional loadings and the latter one was a non-proportional loading where principal direction of stress and strain was changed in a cycle. Four kinds of waveforms (PP, PC, CP and CC) were employed in order to evaluate an effect of strain rate on the lives. F82H showed that failure life was affected by multiaxial strain path and reduction in the life due to non-proportional straining could be seen. However, the effect of strain rate on the lives was small.
