Official Answer
Answer
Carbon steel (SAE 1070-1090) wave springs are susceptible to hydrogen embrittlement during acid cleaning and electroplating (e.g., zinc or cadmium). Atomic hydrogen $(\text{H}^+)$ diffuses into the grain boundaries of the high-strength steel, causing brittle fracture at stresses well below the yield point. To mitigate this, the manufacturing process must include a 'baking' cycle. According to ASTM B633, parts must be baked at $375^{\circ}F \pm 25^{\circ}F$ ($191^{\circ}C$) for at least 4 to 24 hours, depending on the hardness (HRC), as soon as possible after plating (ideally within 4 hours). For critical automotive safety components, many engineers specify mechanical plating or passivated stainless steel to eliminate this risk entirely.
