Discuss the effect of passivating 300-series stainless steel wave springs on their cyclic life in salt spray environments.

Passivation (per ASTM A967) is a chemical treatment using nitric or citric acid to remove 'free iron' from the surface of the wave spring. For 302 or 316 stainless steel, this process enhances the protective chromium-oxide layer. While passivation does not inherently change the bulk mechanical properties, it prevents the formation of pit corrosion sites. In cyclic applications, pits act as stress concentrators ($K_t$) that significantly accelerate fatigue crack initiation. By eliminating these sites, passivation ensures that the fatigue life calculated using $S_{alt} = \frac{S_{max} - S_{min}}{2}$ remains valid in corrosive environments, preventing premature failure due to corrosion-fatigue interaction.