CRYSTALLIZATION OF MOLD FLUX FOR CONTINUOUS CASTING OF STEEL BY HEAT TREATMENT
In continuous casting of steel, mold flux is used to prevent surface defects, such as longitudinal cracks. The crystallization of mold flux promotes mild cooling of the steel shell, but crystallization behavior has been still uncertain. Therefore, this study has been carried out to analyze the crystallization processes of mold flux. One kind of mold flux was used in this work. CaO/Si0 <,2> and B.P. were 1.2 and 1180℃, respectively. This mold flux was melted at 1350℃ for 20 minutes in a graphite crucible, and it was quenched to a glassy state. The glassy specimens were heat-treated at several temperatures (from 500℃ to 900℃) for 3 hours. The grain size was measured by the mean lineal intercept. The crystallization behavior on the surface from glassy state was also observed by laser confocal microscope with infrared furnace. When the specimens heat-treated above 600℃, the grains appeared. It was confirmed by XRD to be cuspidine. The grain size became large with rise of heat-treated temperature. It is considered that the nucleation rate as well as the growth rate as a function of temperature affects the grain size. When many fine crystals appeared inside of the specimen, the surface became rough. Both of rough surface and fine crystals supposed to increase the thermal resistance in the mold.
Mold flux Crystallization Heat-treatment Continuous casting
Hidenori Mizuno Hisao Esaka Kei Shinozuka Manabu Tamura
Dept. of Materials Science and Engineering, National Defense Academy 1-10-20 Hashirimizu Yokosuka, Kanagawa, 239-8686 Japan
国际会议
大连
英文
447-454
2007-08-19（万方平台首次上网日期，不代表论文的发表时间）