HYDROGEN DIFFUSION AND ACCUMULATION IN AUTOMOTIVE FASTENERS

Permeation plating, and baking tests were carried out to determine the susceptibility of a newly developed steel (BHS-1) to absorb and diffu se hydrogen in comparison to the currently used type 1022 (UNS G10220) and type 4037 (UNS G40370) steels. The effective diffusion coefficien t (D-eff) of hydrogen in BHS-1 was slightly lower than in the traditio nal steels: however, the ability to absorb hydrogen during plating and to release hydrogen during baking was comparable. Acidic and alkaline zinc-plating processes dissolved similar amounts of hydrogen into all of the studied steels.