Preparation of Cu–Ni–Fe alloy coating and its evaluation on corrosion behavior in 3.5% NaCl solution

In this paper, an attempt had been made to prepare a Cu–Ni–Fe alloy coating for improving the corrosion resistance of the low-carbon steel. The surface heat treatment of coated low-carbon steel was performed at 1000 °C for 3 h under hydrogen atmosphere. The structure and microstructure of coatings was separately analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the samples was evaluated by potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS). Results indicated that a compact alloy coating was formed on the surface of low-carbon steel and the Ni content had a prodigious impact to the microstructure, composition and structure of Cu–Ni–Fe alloy coating. Apart from that, significant improvements in corrosion resistance were achieved by using the Cu–Ni–Fe alloy coating, which constituting of homogeneous γ-phases.

► An uniform Cu–Ni–Fe alloy coating constituted of homogenous γ-phases was prepared on the surface of low-carbon steel.
► The increase of Ni has a significant promotion to produce a uniform and homogenous Cu–Ni–Fe alloy coating.
► Electrochemical test results indicated the excellent corrosion resistance of the coating with high Ni content.
► EIS test and results demonstrated the surface homogeneity or compactness of the coating with high Ni content.