60 Numerical Evaluation of the Choo and Lee’s Method for Calculating Hydrogen Detrapping Activation Energies Available to Purchase

In the hydrogen thermal desorption analysis, the Choo and Lee’s method, which is widely used for estimating the detrapping activation energy, has been critically assessed numerically focusing on the effects of hydrogen diffusion in the specimen. The numerical simulation of the fundamental reaction-diffusion equation has been performed on the hydrogen desorption process in pure iron to separate successfully the desorption peak of trapped hydrogen from that of hydrogen diffusion. We found that the reduction of the estimated detrapping activation energy with increasing the specimen size is due to hydrogen diffusion. We also found that the initial hydrogen distribution influences the dependence of the detrapping activation energy on the specimen size.