20Cr2Ni4A钢表面WC增强铁基涂层耐磨性能的研究

目的 制备优异的耐磨性涂层用于机械零部件表面,可有效地提高其使用寿命,减少机械设备因磨损失效而带来的各类故障.方法 以20Cr2Ni4A合金钢为基体材料,利用激光熔覆技术,制备了铁基涂层和铁基/WC复合涂层.采用X射线衍射仪(XRD)、金相显微镜、扫描电子显微镜(SEM)、HV-1000显微维氏硬度计,分别对铁基涂层和铁基/WC复合涂层的相组成、组织形貌、显微硬度进行表征.利用HRS-2M型高速往复摩擦磨损试验机对铁基涂层和铁基/WC复合涂层的磨损性能进行研究,并分析其磨损机理.结果 两种涂层的显微硬度与基体相比改善较大,其中铁基/WC复合涂层改善最为明显,表面平均硬度值为610HV.以直径为6 mm的GCr15对磨球为摩擦副,铁基涂层的平均摩擦因数为0.53左右,磨损量为0.1432 mm3,而铁基/WC复合涂层的平均摩擦因数为0.36左右,磨损量为0.05935 mm3,与铁基涂层相比,20Cr2Ni4A合金钢表面结合铁基/WC复合涂层的硬度提高了17％左右,磨损量减小了58.6％,具有良好的耐磨损性能.结论 铁基/WC复合涂层因其表面存在W2C、WC、Fe3C等物相,能够均匀分布在铁基涂层上作为耐磨骨架,显著提高了涂层的硬度和耐磨性能.

Study On Wear Resistance of 20Cr2Ni4A Steel Surface WC Reinforced Iron-based Coating

To prepare excellent wear-resistant coatings for the surface of mechanical parts, which can effectively increase their service life and reduce various failures caused by mechanical equipment wear. Using 20Cr2Ni4A alloy steel as the matrix material, the iron-based coating and the iron-based/WC composite coating were prepared by laser cladding technology. By using X-ray diffraction (XRD), metallurgical microscope and scanning electron microscope (SEM), HV-1000 micro Vickers hardness tester, the phase composition, structure, morphology and microhardness of iron-based coating and iron-based/WC composite coating are characterized respectively; HRS-2M high-speed reciprocating friction and wear tester was used to study the wear resistance of iron-based coatings and iron-based/WC composite coatings, and analyze their wear mechanisms. The microhardness of the two coatings was improved more than that of the substrate. Among them, the iron-based/WC composite coating was improved the most, with an average surface hardness of 610HV. Taking GCr15 with a diameter of 6 mm as the friction pair, the average friction coefficient of the iron-based coating is about 0.53 and the wear amount is 0.1432 mm3, while the average friction coefficient of the iron-based/WC composite coating is only about 0.36, and the wear amount is only 0.059 35 mm3. Compared with the iron-based coating, the hardness of the 20Cr2Ni4A alloy steel surface combined with the iron-based/WC composite coating is increased by about 17%, and the amount of wear is reduced by 58.6%, which shows good wear resistance. W2C, WC, Fe3C and other phases, which are evenly distributed on the iron-based coating as a wear-resistant framework, can significantly improve the hardness of the coating and wear resistance.