Answer
Creep is the time-dependent deformation of a material under a constant stress lower than its yield strength, occurring at elevated temperatures. If a wave spring made of $302$ Stainless Steel is operating at $500^{∘}F$ ($260^{∘}C$), it is near its maximum operating limit. The atomic mobility increases, allowing dislocations to climb and glide, resulting in a loss of free height $H_f$ and consequently a loss of load $P$. Troubleshooting involves measuring the height loss over time. A material upgrade to $17-7PH$ CH900 or, for even higher stability, Inconel X-750 is recommended. Inconel X-750 maintains its elastic properties up to $1300^{∘}F$ due to its $\gamma'$ strengthened matrix, which effectively resists the creep mechanism at the $500^{∘}F$ threshold.
