Change in Hydrogen Thermal Desorption Characteristic of Reduced Activation Ferritic/Martensitic Steel with Creep

Abstract

The change in hydrogen thermal desorption characteristic of reduced activation ferritic/martensitic (RAFM) steel for fusion reactor blanket due to creep was investigated to examine the applicability of thermal desorption analysis (TDA) to remaining-life assessment. The hydrogen charging into creep damaged specimens was conducted by means of cathodic electrolysis. The hydrogen-charged samples were subjected to the TDA for the measurement of hydrogen evolution curve. The experimental results revealed that the evolution curve was changed only by creep depending on the test conditions, and the amount of hydrogen desorbed during the analysis (C_H) increased with increasing the creep life consumption. A vacancy-type defect and dislocation, which were introduced by the electron beam irradiation and the cold rolling respectively, had a large influence on the desorption characteristic, but they were by no means causes of the change in desorption characteristic with creep. It was also found that the C_H was successfully arranged with the parameter derived based on the creep void growth’s law, irrespective of test conditions. The results obtained in this study indicated that the TDA could be a strong tool for the creep damage detection and remaining-life assessment of RAFM steel.