Official Answer
Answer
Inconel X-750 (AMS 5699) is a nickel-chromium alloy specified for wave springs operating in environments exceeding $700^{\circ}F$ ($371^{\circ}C$), where standard stainless steels would undergo rapid stress relaxation. The material is typically precipitation hardened after coiling. For high-temperature service, the #1 Temper (heat treated at $1350^{\circ}F$ for 16 hours) is preferred over the spring temper to optimize creep resistance. In gas turbine seals, Inconel X-750 wave springs maintain their preload despite thermal cycling, preventing bypass leakage. The design must account for a lower Modulus of Elasticity ($E ≈ 31 imes 10^6$ psi) compared to carbon steel, requiring slightly different geometry to match load requirements.
