Effect of CaF2 and MnO on Mold Powder Viscosity and Solidification During High-Speed Continuous Casting

Abstract

Mold powders (MP) are used as raw materials in steel smelting production. In this work TiO2, Na2CO3, MnO, and ZnO are used in a MP composition in order to reduce the CaF2 content or to replace it; CaF2 is used in order to prepare powder, similar to the commercial powder used in steel pouring. Agroove viscometer is used to study MP specimen viscosity, and x-ray diffraction XRD and scanning electron microscopy SEM are used for analyzing specimen behavior during crystallization. Results of studies show that there is cuspidine in XRD diffraction patterns of some specimens. It is established that glassy phase white crystals of cuspidine formed make it possible the regulate MP viscosity required for forming a lubricating layer between mold walls and a steel ingot shell. With use of MnO in MP in an amount of about 4 wt.% (apart from MnO within a specimen chemical composition) alongside F− in an amount of 2 wt.% low-fluorine MP specimens are prepared that may serve as a substitute for MP normally used in steel continuous casting.