12th International Conference on Zinc & Zinc Alloy Coated Steel Sheet - GALVATECH 2021

Zinc coated high strength steel sheets are applied to the automotive part due to the superior corrosion resistance and the lightweight of car body. The hydrogen absorption into the high strength steel sheet has been known to be promoted by zinc coating during corrosion, however, its behavior has not been clarified. In this study, the effect of corrosion status of zinc coating on the hydrogen absorption behavior was investigated. Dry-wet corrosion test was conducted after applying NaCl solution to the zinc coated steel sheets. The permeating hydrogen during the corrosion test was measured by electrochemical technique. It was found that the hydrogen permeation was not observed at early stage of corrosion while significant hydrogen permeation was observed at middle stage of corrosion. Then, the hydrogen permeation decreased gradually at later stage of corrosion. In order to clarify the mechanism of this behavior, surface morphologies of corroded specimens were analyzed by Electron Probe Micro Analyzer. It was found that the hydrogen permeation was observed when the steel substrate was partially appeared, indicating that galvanic corrosion is related to the hydrogen permeation.