Official Answer
Answer
Elgiloy should be specified when a combination of extreme corrosion resistance, high fatigue strength, and high-temperature stability (up to $450^{\circ}C$) is required. It is particularly resistant to sulfide stress cracking (SSC), making it a favorite for both aerospace and sour-gas oil applications. Its Modulus of Elasticity is approximately $200$ GPa, similar to steel, but it maintains its spring properties under much harsher conditions. In aerospace, Elgiloy is used in fuel systems and engine controls where failure is catastrophic. The material is typically aged at $480^{\circ}C$ for 5 hours after coiling to achieve its full mechanical properties, providing a yield strength that can exceed $250$ ksi.
