The 9th International Conference on Surface Engineering (ICSE 2024)

Abstract. Oil and gas extraction equipment such as fracking pumps often fail due to friction and wear of key components as oil resources are depleted. Laser cladding technology was used to prepare the SDNi45 coating to improve the service life of the fracturing pump plunger. The microstructure of the coating was analyzed in detail by employing XRD and SEM equipped with EDS. The hardness was tested using a microhardness tester and the tribological properties were investigated using a performance tester. The results show that the phase composition of the coating mainly consists of γ-Ni, WC, W₂C, Cr₂₃C₆, Cr₇C₃, Fe₂B, and Fe₃W₃C. The bottom part of the coating is primarily columnar crystals, and there are also WC particles that are not completely dissolved after sinking. The middle and upper parts are mainly agglomerated reticulated fine grain, and there are also many secondary generated irregular carbides. The average microhardness of the coating reaches 496.5 HV_0.2, which is about 2.5 times higher than that of the substrate, due to fine-grain and second-phase strengthening effects. The coatings have excellent wear resistance which is mainly due to the γ-Ni base phase providing sufficient plasticity, the fine grain reinforcement and second phase reinforcement providing high hardness, and the C element providing some viscosity. The wear mechanism is mainly abrasive and adhesive wear. This study provides a new option for the surface-strengthening process of fracture pump plungers.