Electrochemical Detection of Hydrogen Generated by Atmospheric Corrosion of Scratches in Zinc Coated steels

—Effect of the Scratched Area—

Abstract

A micro-electrochemical cell for detecting permeated hydrogen, which is generated by atmospheric corrosion at small scratched areas on coated steel, was developed. It is possible to measure hydrogen permeation currents in the nano-ampere range. Using this cell, the influence of the scratched area on the hydrogen generated by the corrosion was investigated. The formation of galvanic couples between steel substrate and coating plays an important role in the generation of the hydrogen during atmospheric corrosion, and the amount of permeated hydrogen increases with larger areas of scratches.