Defect reduction is one of the most important goals in continuing rese
arch to improve remelting technologies, such as vacuum arc remelting,
electroslag remelting, or hearth melting (plasma or electron beam), of
specialty alloys. Ingot defects may originate from several sources in
these processes, such as foreign materials in the melt stock or elect
rode, drop-in material from the furnace interior, and solidification d
efects. Laboratory- and industrial-scale melting experiments are used
by Sandia National Laboratories and the Specialty Metals Processing Co
nsortium to determine relationships between melt-processing conditions
and defect formation. Examples described here include freckle formati
on, a solidification defect in large insets of alloy 625 (electroslag
remelting), and alloy 718 (vacuum are remelting). These examples demon
strate how integrated melting experiments, process modelling, and inse
t analysis can guide the control of melting conditions to reduce defec
ts.