Title: Reduction of Wustite in Oxygen-Potential Gradient
Abstract: This study was performed to ascertain the authors’ consideration that the magnitude of the flux of cation vacancy diffusing into the reaction interface may determine the morphology of reduced iron. Wustite plates of about 1.5 mm thickness and wustite foils produced by the unidirectional oxidation of iron foils of 200, 70 and 25 μm thicknesses in situ were used as specimens. In the reduction of wustite plates, pores were formed in wustite before iron formation, and thereafter iron was formed on the pores. A region of the highest reduction degree was located not on the exterior surface in contact with the reducing gas but in a place distant from the surface. In the reduction of wustite foils, the reaction interface receiving the in-flux of vacancies advances much more rapidly than that not receiving it. The effect of cation vacancies diffusing into the interface on the distance between iron nuclei and the elongation rate of pores in wustite was discussed.