Naoya Miyauchi, Tomoya Iwasawa, Yoshiharu Murase, Taro Yakabe, Masahiro Kitajima, Shoji Takagi, Tomomi Akiyama, Satoka Aoyagi, Akiko N. Itakura
Applied Surface Science 527 146710-146710 2020年5月 査読有り
We have improved an electron stimulated desorption (ESD) apparatus to obtain the time evolution of hydrogen permeation for cold-worked stainless steel. Hydrogen permeation through grain structures was visualized by using the operando hydrogen microscope combining ESD and hydrogen supply system. The diffusion coefficients in grains were calculated from time evolution curves of hydrogen permeation. Principal component analysis (PCA) of hydrogen maps was used to classify crystal grains by the degrees of hydrogen diffusion and permeation flux. Grain structures such as the ratio of austenite/martensite, crystallographic orientations and coherent/random grain boundaries were determined by electron backscatter diffraction (EBSD) analysis. The areas with high-speed and high flux permeation of hydrogen were characterized as smaller austenitic grains with grain boundaries. The usefulness of a combined ESD-PCA-EBSD analysis on hydrogen permeation in materials was demonstrated in the present study.