Effect of process parameters on microstructure and tribological properties of Ni60A/Cr3C2 laser cladding on 60Si2Mn steel

Abstract

To improve the surface performance and service life of the arc-shaped nail teeth, a key component in pre-sowing film recovery machines, Ni60A/Cr3C2 composite coatings were deposited on the surface of 60Si2Mn steel using laser cladding technology. A numerical simulation of the temperature field was conducted for different process parameters based on the ANSYS secondary development language APDL and life–death element technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), three-dimensional morphometry, and X-ray photoelectron spectroscopy (XPS) were also used to analyze the microhardness, microstructure, elemental distribution, and wear resistance of the composite coatings, respectively, to investigate the optimum combination of laser coating parameters. Results show that the temperature field demonstrates a “comet-like” distribution, forming an elliptical melt pool. The average error between melt pool depth and experimental results under this model is 5.1 %. The process parameters affecting the quality of the coating are presented in order of priority: scanning rate, powder feed rate, and laser power. Composite coatings exhibit precipitation of new phases such as γ-Ni-based, NiO, M7C3 (M = Cr, Mn), and M23C6 type. The optimum combination of laser cladding parameters (T6) is 1800 W laser power, 5 mm/s scanning rate, and 8 g/min powder feed rate. T6 coating exhibits a good metallurgical bond with the substrate and a microhardness of 902 HV0.1. Wear of the T6 coating is mainly in the form of abrasive wear, while wear of the base material is in the form of severe adhesive and abrasive wear. The wear and surface roughness of the T6 coating is only 13 % and 39.5 % than those of the 60Si2Mn base material, and the wear depth is reduced by 77 %. This study can provide a reference value for the use of surface technology to enhance the comprehensive performance of agricultural machinery and equipment.