Study on the absorption of Al2O3 inclusions by mold slag for the continuous casting of high-titanium steel
In order to solve the problem that the performance of the mold slag changed under the high-titanium steel and slag reaction and the absorption of the inclusion into mold slag,types of inclusions formed in high titanium molten steel and the amount of inclusions formed at different temperatures were calculated by means of thermodynamic calculation.Besides,according to the formation of inclusions,the performance of the traditional CaO-SiO2 system and the newly developed low reactivity BaO-Al2O3-SiO2-TiO2 system with different percentage of Al2O3 absorption was compared through the performance measurement of mold slag,and the absorption rates of the two types of inclusions were compared by the rotating cylinder method.The thermodynamic calculation shows that with the aluminum mass fraction of the high-titanium steel in this study 0.03%and the titanium mass fraction 0.40%,and the inclusion generated in the molten steel is Al2O3.In actual production,titanium oxides may be formed due to the local composition difference in the molten steel.Results show that the viscosity and melting point of the two types of slag increase with the increase of the content of alumina absorbed by the slag,but the newly developed low reactivity slag has less change than that of CaO-SiO2 system,and its performance is more stable.By rotating cylinder experiment,it can be seen that the absorption rate of CaO-SiO2 and BaO-Al2O3-SiO2-TiO2 mold slag is within(8-12)× 10-3 g/(cm2·min)and(10-13)× 10-3g/(cm2·min),respectively,and the latter has stronger absorption capacity on inclusions.Therefore,the designed BaO-Al2O3-SiO2-TiO2 low reactive mold slag has the potential to be used for the casting of high-titanium steel with higher titanium content.