COMPARISON OF NETWORK LAYER FORMATION BEHAVIOR BETWEEN Al_2O_3-SiO_2-C CONTINUOUS CASTING NOZZLE AND MOLTEN STEELS WITH THE CHANGE OF Al AND Ti CONTENT

摘要

To investigate the reaction mechanism and the network layer morphology characteristics of casting nozzle with the change of Al and Ti in molten steels, reaction tests were done between Al_2O_3-SiO_2-C nozzle refractory and molten steels such Al killed medium carbon, Al killed low carbon, Ti killed low carbon, Ti added Al killed low carbon steel. Based on the chemical composition change of molten steel during reaction and thermodynamic analysis, reaction mechanisms were investigated. Through the microscopic observation of reacted refractory specimen, Ti killed and Ti added Al killed steel have a thin network layer due to high wettability on network layer with alumina and titania rich particles, Al killed steels have a thick and porous network layer due to low wettability on network layer with alumina particles.