Removal of hydrogen from 304 austenitic stainless steel at room temperature by the electro-oxidation method

Hydrogen embrittlement effect can negatively affect properties of metal parts in energy industries.Recently the electro-oxidation (EO) method has been developed to restore hydrogeninduced mechanical degradation, showing good efficiency to remove hydrogen in ferritic and martensitic steels and recover their mechanical properties.However, the understanding about the hydrogen trapping sites and the type of removed hydrogen by the electro-oxidation (EO) method, and its universal applicability is still unclear.Here, as the first example to assess the effectiveness of the EO method to remove hydrogen in austenitic steels, widely used 304 stainless steel was investigated to evaluate removal of hydrogen and reveal hydrogen trapping states and removal ratio through thermal desorption analysis (TDA), in which hydrogen was replaced by its deuterium (D) isotope to eliminate intrinsic hydrogen interference.It was found that for gaseous charged deuterium, deuterium can be removed by the EO method at room temperature with the efficiency higher than that of desorption in the ambient condition, and the removal ratio of deuterium was linked with the charging temperature.The results demonstrate the effectiveness of the EO method and help to reveal