Official Answer
Answer
At cryogenic temperatures, 302 Stainless Steel undergoes a martensitic transformation, which increases its tensile strength $S_u$ and spring rate $K$ by approximately 10-15 percent. However, this is accompanied by a significant decrease in elongation and fracture toughness. For LNG (Liquefied Natural Gas) valve seals, this means the wave spring will provide a higher seating force but will be more brittle. Designers must ensure the spring is not subjected to shock loading at these temperatures. Materials like A-286 or Inconel 718 are often used instead if high ductility must be maintained at temperatures near absolute zero.
