M. Nakai, K. Nagai, T. Kunieda, Y. Murata, M. Morinaga, Nagoya University, Nagoya, Japan; S. Matsuda, M. Kanno, The University of Tokyo, Tokyo, Japan

Summary: The mechanism of high-temperature steam oxidation was investigated with pure iron and a 10%Cr steel from a viewpoint of hydrogen dissolution into the oxide scale during the steam oxidation. Then, the dissolved hydrogen effect on the defect structure in the oxide scale was discussed using an electroneutrality theory.