Influence of composition and microstructure on performance of wrought heat resisting alloys

A review of the historical development of heat resisting stainless steels and high temperature alloys reveals that advances have occurred in three waves or generations over the past 50 years. These developments are the result of increased technical understanding of how alloying elements influence microstructure. Advances in steelmaking practice also have contributed greatly to these improvements. While there are a number of important ferritic stainless steels used in high temperature service, the scope of this article encompasses the austenitic stainless and nickel-base alloy systems.