Abstract
In our previous investigation of the behavior of oxide inclusions in steels during hot-rolling, the specimens containing uniformly a certain amount of specific oxide inclusions were made using the powder metallurgical technique. These specimens were somewhat more porous than those manufactured by melting. When the specimens with high porosity were heated in the air, complex oxide inclusions were frequently formed in those specimens, because the oxide inclusions inserted were combined with the iron oxides which were formed during heating. This investigation was carried out to know how change would occur on Al2O3, TiO2 and SiO2 inclusions in the above specimens.
Consequently, Al2O3, TiO2 and SiO2 changed easily into FeO. Al2O3 (Hercynite), 2FeO·TiO2 (Pseudo-brookite) and 2FeO·SiO2 (Fayalite) respectively. Particularly, the complex oxide 2FeO·TiO2was identified by various experiments, since, in our previous experiment, it could not be identified by A. S. T. M. cards. Furthermore, the rates of formation of the complex oxides were measured, by means of the X-ray diffraction technique, on the basis of the diffusion reaction between particles of the powder mixtures: Fe, Fe2O3 and simple oxides. The activation energy in the formation of those complex oxides was also calculated and discussed.
