Morphology and Chemistry of Oxide Inclusions After Al and Ti Complex Deoxidation

Abstract

The morphology and chemistry of oxide inclusions after various Al and Ti complex deoxidation sequences were investigated at 1600 degrees C. Depending on the addition sequence of Al and Ti deoxidants and the holding time, the morphology and the chemistry were changed. In particular, when Ti was added prior to Al, spherical Al2O3 oxide inclusions with hollow holes were frequently observed, which is reported for the first time. On the other hand, when Al was added prior to Ti, Al2O3 inclusion formed. When Al and Ti were added simultaneously, Al-Ti-O oxide inclusion formed in the beginning and was transformed to Al2O3 inclusion. Based on the experimental results, the formation rnechanism of the oxide inclusions after Al-Ti deoxidation was proposed. The nozzle clogging of Ti bearing Al killed steel was also discussed based on the experimental results.