Effects of Hydrogen Charging on Mechanical Properties of CLAM Steel at Different Strain Rates

The China low-activation martensitic (CLAM) steel has been proposed as a candidate structural material for nuclear fusion reactors. It is essential to study the influence of hydrogen charging and strain rate on the tensile behavior of CLAM steel considering its service environment. In this study, CLAM steel was investigated using tensile tests operated at room temperature before and after hydrogen charging. The results showed that the elongation loss increased significantly with the increase of the hydrogen charging current density at either a low or a high strain rate, which is related to the hydrogen content in the steel. The hydride was systematically studied, including the morphology and the thermal stability as well as the effects on mechanical properties. The possible mechanism of the formation of hydride during hydrogen charging has been analyzed based on the interaction between alloying elements and hydrogen.