What are the risks of using SAE 1070 carbon steel spiral rings in a marine environment, and how does zinc-flake coating mitigate them?

SAE 1070 carbon steel is highly susceptible to uniform corrosion and pitting in chloride-rich marine environments, leading to a reduction in the effective cross-sectional area and subsequent thrust capacity loss. Zinc-flake coatings (e.g., Geomet or Magni) provide sacrificial protection and a barrier layer. Unlike traditional electroplating, zinc-flake coating is non-electrolytic, which significantly reduces the risk of hydrogen embrittlement. This is crucial for retaining rings because their high hardness (HRC 45-52) makes them extremely sensitive to hydrogen-induced delayed fracture.