Liquid Metal Processing & Casting Conference (LMPC 2022): Electoslag Refining II
Program Organizers: Matthew Krane, Purdue University; Mark Ward, University of Birmingham; Abdellah Kharicha, Cdlab Mhd Montauniversitaet

Tuesday 1:40 PM
September 20, 2022
Room: Grand Ballroom
Location: Bellevue Hotel

Session Chair: Alain Jardy, Institut Jean Lamour

1:40 PM Introductory Comments

1:50 PM
Nitinol Electroslag Remelting: Initial Slag Study: Kyle Fezi¹; Paul Jablonski²; Martin Detrois²; Jeff Slater¹; Beth Stehulak¹; ¹Fort Wayne Metals; ²National Energy Technology Laboratory
    Nitinol’s unique shape memory and super-elastic properties make it attractive for many applications in biomedical, automotive, aerospace, industrial refrigeration, and waste heat reclamation industries. The fatigue performance is limited however, by non-metallic inclusions (NMI) formed during the traditional VIM/VAR or multi-VAR process. ESR is a potential alternative melt process and is commonly used to refine ingot chemistry and enhance the metallurgical structure of many superalloys and specialty steels, but no study on ESR of Nitinol has been reported to date. The key to establishing a successful ESR process is selecting a compatible slag. In this study, several different slag chemistries are evaluated for their compatibility with Nitinol. One slag chemistry is chosen, along with a control, to produce four Nitinol ESR ingots. Pursuit of a novel slag chemistry for adequate Nitinol refinement is discussed.

2:20 PM
Design of ESR Slags According to Requested Physical Properties. Part 4: Thermal Conductivity: Krzysztof Wroblewski¹; Piotr Wroblewski²; ¹Rowan University; ²Wroblewski Consulting
    The pool profile, local solidification time and subsequently microstructure of the ingot, melting of the electrode, mass transfer coefficient, diffusivity, depend on the thermal conductivity of molten slag Λ_l. Thermal conductivity of the crust/skin Λ_s affects mostly the quality of the ingot’s surface. Both values form important constituents of multifunction Γ(T,d,η,κ,Λ_l,Λ_s) which for requested working temperature, (T), density (d) viscosity (η), electrical conductivity (κ), void fraction in solid (ε), thermal conductivity at the temperature T, (Λ_l) and at the solidus point (Λ_s) defines all six components (CaF₂, CaO, MgO, Al₂O₃, TiO₂, SiO₂) slags of requested properties. Literature data was used to calculate parameters of correlation between thermal conductivity of molten, and solid slag at the process and solidus temperatures, respectively. Updated numerical algorithm presented in Part 1 provided solutions that are in close agreement with literature data, as well as those advertised by Wacker Chemie AG.

2:50 PM Break