2015 Volume 58 Issue 10 Pages 387-391
Permeation behavior of hydrogen from the backside of a stainless steel membrane (SUS304) was investigated by electron stimulated desorption (ESD) method. Detection system of ESD ion and a sample holder with hydrogen reservoir were incorporated in the scanning electron microscope. The distributions of hydrogen concentration on the sample surface were observed by ESD ion images. The thickness of stainless steel membrane is 100 μm. The membrane has austenite structure including martensite dislocations, and the size of austenite grains, 100-150 μm, is comparable to the thickness of membrane. The ESD ion images are observed at different temperatures, which are controlled from RT to 573 K with 50 K steps. High concentration sites of hydrogen at 323 K are different from the incremental sites at 473 K, suggesting that the former increase is due to the diffusion through martensite phase and the latter is due to austenite phase.