Paul D. Jablonski¹, Martin Detrois¹; ¹National Energy Technology Laboratory

Vacuum induction melting (VIM), electro-slag remelting (ESR) and vacuum arc remelting (VAR) are all techniques used to make high quality ingots of complex chemistries. In some cases, all three are used, e.g., alloys for aerospace applications and increasingly those for fossil power applications under extreme conditions. As such, research on alloys of this class require access to a variety of melting capabilities. In this report we discuss our recent experiences with a laboratory scale (200mm/200kg) combination VAR/ESR furnace. The focus will be on the ESR operation, and its use for control of unwanted elements. Two master alloys are considered: Ni-25Cr and Ni-30Co-30Cr, processed through a combination of VIM and ESR. The role of the alloy additions in modifying the melting characteristics lowering the tramp element content and residual inclusions were determined computationally and confirmed experimentally. The usefulness of these master alloys as experimental remelt stock will also be discussed.