The Suppression of transformation of γ-FeOOH to α-FeOOH accelerating the steel corrosion in simulated industrial atmospheric environment with a DC electric field interference

The initial corrosion of steels exposed to the simulated industrial atmospheric environment with a direct current (DC) electric field for 30 days was investigated using weight loss, electrochemical and characterisation methods. The results show that the steel weight loss increased with the increase in DC electric field intensity. The steels exposed to the DC electric field interference exhibited a higher corrosion rate than the blank samples during the exposure. The microstructural studies reveal that the existence of the DC electric field favours the growth of the gamma-FeOOH, while suppresses the transformation of gamma-FeOOH into alpha-FeOOH during the 30 days' exposure, as a result of decreasing the protective ability and stable property of the rust layer. The amount of porous gamma-FeOOH enhances the transmission of oxygen and conductivity of the whole rust layer. All these induce an accelerated effect of DC electric field on the initial steel corrosion in simulated industrial environment.