In this study, Ni-P electroless coating was deposited on carbon steel by a new method called SLHS (substrate local heating system) which makes a higher rate of deposition possible without the risk of decomposition of electroless baths. The effects of pH and temperature on plating rate, composition, surface morphology, hardness and corrosion of the coating in SLHS condition (T_sub = 190 °C, T_bath = 80 °C) were investigated. In addition, the impact of heat-treatment at 400 °C for 1 h on hardness, morphology and microstructure was also studied. Samples prepared by this method were characterized by Scanning Electron Microscopy/Energy-Dispersive x-ray analysis, Light Microscope and x-ray diffraction. They were then submitted to Vickers microhardness and tribological tests. The deposition rates of electroless nickel (EN) coating were first estimated by weight gain method and then by light and scanning electron microscopy. Electrochemical Impedance Spectroscopy (EIS), Tafel polarization and salt spray tests were then used to evaluate the corrosion properties of the coatings. The study shows that maximum deposition rates for conventional and SLHS samples were approximately 20 µm/h and 32 µm/h, respectively. This increase in the plating rate reduces the phosphorus level by nearly 1.5 wt.% for SLHS sample. The corrosion resistance of SLHS sample is improved in comparison to the conventional one.

在这项研究中，Ni-P化学镀层通过一种称为SLHS（基底局部加热系统）的新方法沉积在碳钢上，该新方法可实现更高的沉积速率而无化学镀液分解的风险。pH和温度对SLHS条件下（T _sub  = 190°C，T_浴）的镀层速率，成分，表面形貌，硬度和腐蚀的影响 = 80°C）。此外，还研究了在400°C下热处理1 h对硬度，形态和微观结构的影响。通过扫描电子显微镜/能量色散X射线分析，光学显微镜和X射线衍射对通过这种方法制备的样品进行表征。然后，他们接受了维氏显微硬度和摩擦学测试。首先通过增重方法，然后通过光学和扫描电子显微镜，估计化学镀镍（EN）的沉积速率。然后使用电化学阻抗谱（EIS），Tafel极化和盐雾测试来评估涂层的腐蚀性能。该研究表明，对于常规和SLHS样品最大沉积率分别为约20  μ M / H和32  μm / h。对于SLHS样品，电镀速度的提高使磷含量降低了近1.5 wt。％。与传统的相比，SLHS样品的耐腐蚀性得到了提高。