Abstract:In order to improve the properties of nano-cermet composite electrodeposited coatings, Ni-TiN-GO (Graphene Oxide) composite electrodeposited coatings were prepared on the surface of alloy steel by multi-step electrodeposition process. Its microstructure, composition, microhardness, wear resistance and corrosion resistance were characterized and analyzed, and determine the most suitable multi-step electrodeposition process. On this basis, the coating was post-treatment, the effect of post-treatment on the corrosion resistance of the coating was studied. The results show that the microstructure and properties of the coating obtained by three-step electrodeposition are the best, good bonding with the substrate and the thickness is 24.6 μm, the coating obtained by three-step electrodeposition has uniform and dense surface, and the grain size is about 20nm, and the grains show double preferred orientation of (111) and (200) planes. The microhardness of the electrodeposited coating is 2249.44HV, and the friction coefficient is 0.8. the wear mechanism is mainly weak abrasive wear. The results of Tafel polarization curve test showed that the corrosion potential of the three-step electrodeposited coating is -0.677V, and the self-corrosion current density is 1.71×10-5A·cm-2, After 96h salt spray test, the morphology of the coating did not change obviously. After post-treatment, the self-corrosion potential of the three-step electrodeposited coating shifted positively to 60mV, and the self-corrosion current density decreased by an order of magnitude.