ABSTRACT
The term “superalloys” is used somewhat loosely to describe a wide range of high performance materials which usually combine high strength and corrosion resistance at temperatures above the limits accessible to martensitic steels, i.e. 650°C and above. It is sometimes extended to include chemically or structurally related materials designed to fulfil more specific functions. A common feature of all these materials is the face-centered cubic “austenitic” crystal structure of the matrix phase. Strenghthening is obtained chiefly by solid solution hardening and carbides in the cobalt-based grades 1 and nickel-based sheet alloys, whereas other wrought and cast nickel-and iron-based alloys are also strengthened by precipitation of an intermetallic phase. The present work will be devoted essentially to this latter category, which is most characteristic of a “typical” superalloy.
