Protective characteristics of electroplated iron applied to low carbon steel

The galvanic and general corrosion characteristics of plated iron were evaluated for consideration as a fatigue crack treatment for ASTM A36 steel. The general corrosion rate of the plated iron in a 3.5 wt-% NaCl solution ranged from 2-5 mpy. SEM examination revealed mud cracking as well as pitting of the plated metal. Galvanic corrosion assessment showed that the steel was generally cathodic to the plated iron. The anode/cathode ratio exhibited by the mud cracking morphology projected to a galvanic corrosion rate of 1-2 mpy. Fatigue crack treatments conducted with electroplated nickel exhibited galvanic corrosion that was expected to harm the steel substrate via galvanically assisted crevicing. In contrast, this study showed that the corrosion characteristics of electroplated iron in this application would tend to render the A36 steel galvanically protected.