Official Answer
Answer
Inconel X-750 (UNS N07750) is a nickel-chromium superalloy utilized for wave springs in extreme environments, such as subsea oil and gas valves or aircraft engines. Its primary advantage is its resistance to relaxation and creep at temperatures up to $1300^{\circ}F$ ($704^{\circ}C$). The material is precipitation-hardened, and for spring applications, it is typically supplied in the 'No. 1 Temper' or 'Spring Temper' followed by age hardening. In subsea environments, its resistance to chloride-induced stress corrosion cracking (SCC) makes it indispensable, though designers must account for its higher density and lower modulus ($E \approx 31 \times 10^6$ psi) compared to carbon steel when calculating spring rates.
