Effect of Heat Treatment on Chemical Plating of Ni-Cr-P on 65Mn Alloy Steel

Abstract

The chemical plating of Ni-Cr-P significantly affects the improvement of the structure and characteristics of the metal surface. This study aimed to investigate the impact of various plating solution components and process parameters on the deposition rate and surface hardness of Ni-Cr-P coatings on 65Mn alloy steel. Additionally, the study examined the changes in coating properties resulting from different heat treatment temperatures. The specimens coated with Ni-Cr-P underwent heat treatment at temperatures of 180°C, 200°C, 220°C, and 240°C, respectively. The testing results indicate that the plating layer achieves its highest level of performance when subjected to a heat treatment temperature of 200°C. The heat-treated coating exhibits superior wear and corrosion resistance compared to the 65Mn steel substrate. Additionally, the coefficient of friction decreases from 0.5 to 0.4. The self-corrosion potential shifts positively from -569 mV to -389 mV, and the corrosion current decreases from 61.4 μA to 14.48 μA. Furthermore, the impedance improves from 234 Ω·cm2 to 3512 Ω·cm2.