Numerical estimation of applicability of Choo and Lee's method for evaluating detrapping activation energy

Ebihara, Kenichi   ; Kaburaki, Hideo; Takai, Kenichi*

In order to understand the mechanism of hydrogen embrittlement of steels, it is necessary to evaluate the binding energy between a lattice defect and a hydrogen atom which influences the hydrogen trapping state in steels. Since the binding energy can be evaluated theoretically and experimentally due to recent development of technologies, it may become possible to estimate the binding energy in practical steels. Because the Choo-Lee method for estimating the binding energy from the thermal hydrogen desorption analysis is restricted to the case of the thermal-detrapping-determining hydrogen desorption process, the applicability of the Choo-Lee method was studied numerically. As a result, it was found that the restriction of the Choo-Lee method is relaxed when the hydrogen-charged specimen is held below the temperature at which the hydrogen desorption starts.