Official Answer
Answer
Inconel X-750 (UNS N07750) is specified for wave springs when the application requires high strength at temperatures up to $1300^{\circ}F$ or resistance to chloride-induced stress corrosion cracking (SCC) found in subsea environments. It is often heat-treated to the NACE MR0175 standard for sour gas service. The material's high nickel content provides immunity to many reduction environments, while chromium provides resistance to oxidizing conditions. Its relaxation rate at $1000^{\circ}F$ is significantly lower than that of A286 or 17-7PH, ensuring long-term seal integrity in downhole tools.
