Other applications of superalloys

Abstract

It is the intention in this paper to put into context the development of high-temperature alloys to their present position in non-gas-turbine applications, and to identify new alloy systems capable of improving performance in hostile industrial environments. The rise of superalloys from ferritic steels to the current γ′-hardened nickel-base materials, the best of which experience strength limitations above l000°C, is traced. Desired increases in temperature capability are possible with oxide dispersion strengthened powder alloys, which were originally developed for gas turbine usage and are now being produced on a large tonnage basis by the mechanical alloying (MA) process. The MA technique and commercial alloys are described and examples given of the replacement of more conventional materials by fabricated MA components in a diversity of industries. MA alloys exhibit combinations of strength and corrosion resistance capable of meeting many industrial demands for economic improvements to processing capabilities and efficiencies.

MST/525