Effect of defect on corrosion behavior of electroless Ni-P coating in CO2-saturated NaCl solution
By Sun, Chong; Li, Jiankuan; Shuang, Shuo; Zeng, Hongbo; Luo, Jing-Li
Published in Corrosion Science
2018
Abstract
The effects of defect on the localized corrosion and disbonding behavior of electroless Ni-P coating in CO2 environment were investigated using electrochemical methods and surface characterization techniques. The results show that the Ni-P coating has a good resistance to corrosion disbonding at open circuit potential, even with an artificial defect in the coating. The localized corrosion and the disbonding of the coating occur after the acceleration by cathodic polarization because the coating defects provide effective pathways for the electrolyte to transport through the coating and along the coating/substrate interface laterally. A corrosion model is proposed to well interpret this phenomenon.