Effect of applied low-voltage spatial electric field on the corrosion behaviour of copper in 3.5 wt-% NaCl solution

Electrochemical tests and surface analyses were carried out to study the influence of the external low-voltage spatial electric field (SEF) on the corrosion behaviour of copper in 3.5 wt-% NaCl solution and explore the corrosion kinetics of copper under the SEF. The results show that the presence of the SEF aggravated the corrosion of copper; the results of weight loss tests and electrochemical tests indicated the enhanced corrosion rate of copper as the field strength increased. The X-ray diffraction results of corrosion products suggested that the Cu2O converted to Cu2(OH)3Cl with application of the SEF. The effect of the SEF on the copper proved the increase in corrosion rate was attributed to the enhanced migration of ions towards the sample surface caused by the external SEF. It resulted in more aggressive chloride ions to penetrate into the looser surface corrosion product film, thereby accelerating corrosion.