Scanning Kelvin Probe Study Of Hydrogen Formed During Atmospheric Corrosion

One of the intensively studied issues regarding hydrogen embrittlement of advanced high strength steels (AHSS) is the absorption and diffusion of hydrogen produced by atmospheric corrosion. Scanning Kelvin Probe (SKP) is a tool sensitive enough to detect low amounts of hydrogen formed during atmospheric corrosion. In this work, SKP was used to study the effect of the presence of corrosion products on hydrogen uptake and permeation through AHSSs specimens. Corrosion was initiated on one side of the specimen contaminated with a corrosion activator, while Volta potential mapping on the opposite side allowed for in-situ hydrogen detection. Hydrogen release indicated by low potential areas in the maps corresponded to the locations of corrosion products on the opposite side. This shows that hydrogen entry is linked to the presence of red rust.