Physico-chemical properties of the ESR slags system CaF2-Al2O3-(MgO, TiO2)

Abstract

Purpose: The main task of this work was the developing of new compositions of the ESR slag that would keep the required amount of easily oxidizable elements in the superalloys and have the favourable physicochemical properties. Design/methodology/approach: Thermo-dynamic modeling was applied to estimate of oxidation effect of the slags on the Inconel 718 superalloy. Slag properties (viscosity, electrical conductivity and melting points) were measured by standard methodics. Findings: The effect of slags chemistry on the preservation of the active elements (aluminium, titanium) content in the superalloy while ESR remelting was studied. Physical properties of the several compositions of the slag are prospective for ESR of alloys with high content of active elements were measured. Research limitations/implications: The results of this work allowing development of a new compositions of the slags for ESR of the specific grades of the steel and alloys and making selection of the most effective ones. Practical implications: The obtained data make it possible to successfully select a slag for the ESR processing of the specific grades of steel and alloys in order to achieve the maximum process efficiency and the quality of the ready ingots. Originality/value: The integrated approach for the investigation of slag properties using developed thermo-dynamic model of the ESR process in the protective atmosphere gives us a deep understanding of the slag effect while melting and a resulting content of easy easily oxidizable elements in the superalloy Inconel 718.