Evolution of Inclusions after Cerium and Titanium Addition in Aluminum Deoxidized Fe-17Cr-9Ni Austenitic Stainless Steel

抄録

In this study, the effects of the addition of Ce and Ti on the evolution of inclusions in Al deoxidized Fe-17Cr-9Ni austenitic stainless steel were investigated. When the Ce was added before Ti, Al₂O₃ can be effectively modified into Ce-containing oxides by Ce. With the increase of Ce content, the oxides evolutionary process is as follows: Al₂O₃ → CeAl₁₁O₁₈ → CeAlO₃ → Ce₂O₃. After the addition of Ti, TiN appeared on the surface of oxides except Ce₂O₃. When Ti was added before Ce, due to the simultaneous effects of Ti on the modification of smaller size Al₂O₃ and precipitation of TiN, spherical Al₂O₃–TiO_x inclusion that was completely wrapped by TiN formed. On the other hand, the larger size Al₂O₃ was not significantly modified by Ti, and cannot completely be wrapped by TiN. After Ce was added, the oxides which were not completely wrapped by TiN were modified to Ce-containing oxides. However, Ce could not modify the oxides that were completely wrapped by TiN.