Thermodynamic and Physical Properties of CaF.sub.2- System Slags for Electroslag Remelting of Inconel 18 Alloy

• Published in: Materials science (New York, N.Y.) N.Y.), 2023-01, Vol.58 (4), p.494
• Main Authors: Stovpchenko, G. P, Lisova, L. O, Medovar, L. B, Goncharov, I. O
• Format: Article
• Language: English
• Subjects: Electric properties; Electrical conductivity; Heat resistant alloys; Lime; Nickel alloys; Thermodynamics; Titanium
• ISSN: 1068-820X
• DOI: 10.1007/s11003-023-00690-6

Physicochemical properties (viscosity, electrical conductivity, melting point, thermodynamic activity of oxygen) of (10 - 70)CaF.sub.2 - (0 - 60)Al.sub.2O.sub.3 - (0 - 30)TiO.sub.2 - (0 - 30)MgO slags system are studied. The required content of titanium in the Inconel 718 (0.65-1.15%) can be provided with the studied slags (49CaF.sub.2 - 30Al.sub.2O.sub.3 - 21TiO.sub.2 and 50CaF.sub.2 - 22Al.sub.2O.sub.3 - 18TiO.sub.2 - 10MgO) even if they contain 0.5 - 2% SiO.sub.2. The aluminum content can be adjusted by adding or pre-increasing its content in the remelting electrode. With temperature growth from 1500 to 2500 K, the equilibrium content of Ti in the metal decreases, and of Al - vice versa. The content of titanium at the initial level (1%) in the molten metal is provided at a temperature of 1700 K with 50CaF.sub.2 - 22Al.sub.2O.sub.3 - 18TiO.sub.2 - MgO slag. In comparison with 70CaF.sub.2 - 15Al.sub.2O.sub.3 - 15CaO slag, widely used for superalloy remelting, the studied compositions 49CaF.sub.2 - 30Al.sub.2O.sub.3 - 21TiO.sub.2, and 50CaF.sub.2 - 22Al.sub.2O.sub.3 - 18TiO.sub.2 - 10MgO will increase environmental friendliness of the remelting as a result of CaF.sub.2 content reduction by 20% at comparable values of crystallization temperature and conductivity.