2022 Volume 62 Issue 8 Pages 1561-1572
The oxidation behavior of various reactive elements, such as Al/Ti, B/Si, and rare earth metals (REM), by electroslag remelting (ESR) type slag has been investigated utilizing the systematic thermodynamic analysis based on the calculated activity in the fluoride-containing slags by the ion and molecule coexistence theory (IMCT). The results indicate that the IMCT model can be reliably applied to calculate the activity of each component in the ESR type slag. The oxidation behavior of the various reactive elements is completely different by changing the same component in the slag, such as CaO and Al2O3, during the ESR process. Therefore, it is indispensable to find a key parameter to control the homogeneity of the reactive elements in remelted ingots by comparing the effects of the activity of each component and temperature on the equilibrium content of the various reactive elements in alloy melts. The results demonstrate that the oxidation loss of Al/Ti, B/Si, and REM (Ce and La) can be effectively prevented by employing TiO2, B2O3/SiO2, and CaO during the ESR process. Oxidation behavior of B/Si and Ce(La)/Al is weakly susceptible to temperature fluctuation compared with that of Al/Ti in alloy melts, which can be controlled by adding TiO2.
