Because of its hardness, dimensional tolerance and resistance to hydrogen, cadmium plating has been used to protect steel components in marine environments. However, Cadmium is thought to be toxic and a search is on for an alternative. In this paper, cadmium and zinc-nickel plating/coating were compared in water immersion, temperature cycling, rain, humidity, and salt fog testing.
03248 2003 CP
Cadmium plating has been used to protect steel components in marine environments. Cadmium has been used because of its hardness, close dimensional tolerance, and its ability to restrict hydrogen permeation into or out of steels. However, cadmium is highly toxic to occupational safety and harmful to the environment, thereby necessitating the search for alternative corrosion control coating systems. Alternative plating/coatings to replace cadmium plating have been developed and evaluated for some period of time. In this paper, the environmental performance of the cadmium and zinc-nickel plating/coating systems on 4130 steel were evaluated and compared in water immersion, temperature cycling, rain, humidity, and salt fog testing.
Key Words: cadmium replacement, zinc-nickel coating, zinc-nickel plating, zinc alloy electroplating, corrosion, marine corrosion, salt fog, environmental, blistering