Simulation of hydrogen thermal desorption spectra for iron with strain-Induced vacancy-type defects included

Ebihara, Kenichi   ; Sugiyama, Yuri*; Matsumoto, Ryosuke*; Takai, Kenichi*; Suzudo, Tomoaki   

A hydrogen embrittlement model supposes that vacancies in steel which are generated by hydrogen charging and deformation concurrently cause directly embrittlement. Moreover, a characteristic peak appears in the hydrogen thermal desorption spectrum of such steel. Therefore, it is considered that vacancies and vacancy clusters resulting from vacancy aggregation can be estimated quantitatively by numerically simulating such a spectrum for verifying the model. In this study, the thermal desorption spectra of an iron specimen with strain-induced vacancies was measured, and the spectra was simulated using a model considering the behavior of vacancies and vacancy clusters. The possibility that diffusion of some kinds of vacancy clusters may be slower than the theoretical value was indicated from the result. Furthermore, we discuss the measurement of the thermal desorption curve immediately after the vacancy formation. This presentation includes a part of Metal. Mater. Trans. A52 (2021) 257.