Alloys 625 and 725: Trends in Properties and Applications

Abstract

INCONEL alloy 625 (UNS N06625) has been widely used for over 50 years in the marine and petroleum industries for applications requiring high strength, fracture toughness, fabricability and resistance to corrosion. By increasing the titanium content of the alloy in the presence of its content of niobium, an alloy that can be significantly strengthened by heat treatment is created. By the precipitation of various secondary phases in an austenitic matrix, INCONEL alloy 725 (UNS N07725) offers the high strength of alloy 718 along with the corrosion resistance of alloy 625. The metallurgy of alloy 725 is discussed along with information about its properties, fabrication, and applications.