The corrosion behavior of electroless Ni–P coating in Cl−/H2S environment

At present, the Cl−/H2S corrosion of refinery heat exchanger at low temperature has a great impact on safety production. Aimed at this problem, an amorphous state Ni–P coating was prepared by electroless plating method in this paper. The electrochemical behavior and corrosion resistance of Ni–P coating in Cl−/H2S environment were investigated by means of electrochemical equipment and autoclave, respectively. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) analysis suggest that the Ni–P coating is amorphous state and little microporous appears on its surface. The electrochemical measurement and autoclave test results show that the corrosion resistance of Ni–P coating is superior to that of 316L stainless due to its amorphous state structure and low porosity. The corrosion rate of Ni–P coating in this Cl−/H2S environment is only 0.0011 mm/a.