Answer
SAE 1070 carbon steel is susceptible to hydrogen embrittlement during the pickling and electroplating processes (e.g., Zinc or Cadmium plating) where atomic hydrogen diffuses into the grain boundaries of the high-strength martensitic structure. Under tensile stress, these hydrogen atoms migrate to stress concentration points, leading to brittle fracture at loads far below the yield strength. To mitigate this per AMS 2759/9, the rings must undergo a de-embrittlement baking cycle within $1-4$ hours of plating. Typically, this involves heating the components to $190^{\circ}C$ to $220^{\circ}C$ for a duration of $8$ to $24$ hours, depending on the hardness level and cross-sectional thickness. For critical aerospace fasteners, mechanical plating or stainless steel alternatives (e.g., 302 or 316) are often preferred to eliminate the risk entirely.
