Abstract:
Laser-cladded Fe-based coatings possess the advantages of high preparation efficiency, low cost and high bonding strength between the coating and the base materials, which has attracted extensive attention focusing on the improvement of the corrosion resistance. Ni60A alloyed Fe-based composite coatings were obtained using laser cladding process. The results show that the microstructure of the coatings are found to consist of unevenly dispersed rod-like Cr-rich dendritic crystal grains. As the Ni60A content increases, the corrosion potential shifts positively first and then negatively, while the corrosion current density exhibits an opposite trend, which indicates that the corrosion resistance of the coatings increases initially and then decreases. The 4wt%Ni60A coating has optimum corrosion resistance with a corrosion potential of -0.228 V and a corrosion current density of 9.6×10
-7 A·cm
-2 superior to other Ni60A-added coatings. The electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) analysis were carried out to reveal the corrosion mechanism. The effects rule of Ni60A addition on the corrosion behavior of the coating were analyzed.