Immersion corrosion behavior and electrochemical performance of laser cladded Ni60–CeO2 coatings in 5% NaCl solution

Abstract

Abstract Ni60 coatings with the CeO2 mass fractions of 3%, 6%, and 9% were prepared on S355 steel. The microstructure and phases of obtained coatings were analyzed using an ultradepth of field microscope (UDFM) and X–ray diffraction (XRD), respectively. The effects of CeO2 mass fraction on the immersion corrosion behaviors and electrochemical performances of Ni60–CeO2 coatings in 5% NaCl solution were investigated. The results show that the immersion corrosion rates of Ni60–3%CeO2, –6%CeO2 and –9%CeO2 coatings are 37.1, 24.3 and 49.2 μm/year, respectively, in which the immersion corrosion resistance of Ni60–6%CeO2 coating is the best among the three kinds of coatings. The polarization resistances of Ni60–3%CeO2, –6%CeO2, and –9%CeO2 coatings are 169,867, 228,568, and 51,276 Ω⋅cm2, respectively, and the corresponding charge transfer resistances are 2.66 × 105, 6.68 × 105, and 6.40 × 105 Ω⋅cm2, respectively, showing that the Ni60–6%CeO2 coating presents the best electrochemical corrosion resistance in 5% NaCl solution.