Official Answer
Answer
Inconel X-750 is a nickel-chromium alloy specified for its exceptional creep resistance and stability in extreme environments. However, its high work-hardening rate makes the coiling of wave springs difficult. After coiling, the material must undergo a specific heat treatment (typically $1350^{\circ}F$ for 16 hours) to precipitate the $\gamma'$ phase, which provides its strength. In sour gas ($H_2S$) environments, the material must also comply with NACE MR0175/ISO 15156 standards to prevent sulfide stress cracking. The primary challenge for engineers is the lower elastic modulus ($E \approx 31 \times 10^6$ psi), which requires a thicker cross-section compared to steel to achieve the same spring rate.
