Official Answer
Answer
Even though Inconel X-750 is highly resistant to corrosion, SCC can occur if three conditions are met simultaneously: a susceptible material condition, a corrosive environment (high-temperature steam with trace contaminants like caustic soda or chlorides), and high tensile stress. In wave springs, the highest tensile stresses are on the ID of the waves. If the material was not properly 'Solution Annealed' and 'Age Hardened' per AMS 5699, grain boundary carbides can form, making the material susceptible to intergranular SCC. Failure analysis would show branched, intergranular cracks. Mitigation includes reducing the operating stress through design changes or ensuring a more rigorous heat treatment process to optimize the microstructure.
