Melting Processes and Solidification in Alloys 7 18-625

The present state of melting techniques for IN7 18 and IN625 has well-defined limitations both in terms of the ingot structure and maximum ingot size which is fabricable by the various processes. Although there are methods already in industrial use which would extend both of these limits, since the alloys must be produced at a relatively low cost here are further limitations on the practical manufacturing methods. The underlying scientific problems of solidification, inclusion removal and structure control are discussed with the conclusion that the present ingot structures probably cannot be substantially improved, but the inclusion population could be modified without much additional effort. Suggestions are made as to the possibilities for making larger pieceweights of the alloys should these become necessary for the marketplace. Superalloys 718,625 and Various Derivatives Edited by Edward A. Loria The Minerals, Metals & Materials Society, 1991