Alumina　Buildup　Mechanism　in　Submerged　Nozzle　during　Continuous　Casting　of　Low　Carbon Aluminum-Killed-Steels

Abstract

　The　buildup　slmulator　which　is　circulating　molten　steel　was　developed　to　analyze　the　mechanism　of　alumina　buildup during　continuous　casting． 　Alumina　bulldup　in　simulated　nozzle　and　actual　nozzle　after　service　were　investigated．The　form　of　alumina　buildup　and　mineral　composition　in　simulated　nozzle　were　as　well　as　those　in　actual　nozzle． 　This　simulator　is　sufficient　to　analyze　the　mechanism　of　alumina　buildup． 　Two　types　of　buildup　alumina　were　observed．One　is　derived　from　reaction　between　refractories　and　molten　steel，the　other　is　derived　from　deoxidation　products　of　molten　steel．It　was　found　that　the　ratio　of　the　latter　is　much　more　than　that　of　the　former．