Hydrogen embrittlement is due to the reaction of diffused hydrogen with a metal. Different metals undergo specific reactions, but the result is the same. Reaction with hydrogen produces a metal that is lower in strength and more brittle.
Hydrogen embrittlement of steels is a major problem in all types of cyanide zinc plating. These formulas should not be used for spring tempered or other parts susceptible to this type of embrittlement. Spring tempered parts and other parts susceptible to hydrogen embrittlement should be plated in the acid chloride electrolyte. When no embrittlement whatsoever can be tolerated, the use of mechanically deposited zinc, is the preferable alternative.
A major advantage of mechanical deposition is that it does not produce hydrogen embrittlement in hardened steel during the coating process. However, pronounced embrittlement can be produced in certain cleaning processes. The mild degree of embrittlement that might result from following proper procedures with cleaning methods normally is self-relieving within a day's time at room temperature.
Hydrogen embrittlement may be considered a type of corrosion.
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▪ L - Mechanical Galvanizing