氧化膜对14Cr12Ni2WMoVNb钢QPQ渗层的室温摩擦磨损和腐蚀性能的影响

为了研究14Cr12Ni2WMoVNb钢QPQ(淬火-抛光-淬火)处理后的氧化膜对渗层室温摩擦磨损和腐蚀性能的影响,利用金相、X射线衍射分析、扫描电镜、能谱分析、划痕仪、摩擦磨损试验机和电化学工作站对试样进行了表征.结果表明:氧化膜对渗层室温摩擦学性能的影响与载荷大小有关.在摩擦时间均为4min情况下,载荷较小(50N)时,氧化膜可以降低摩擦系数和体积磨损率;载荷较大(100N)时,氧化膜被破坏无法降低体积磨损率.氧化膜可明显提高渗层的耐腐蚀性能.含氧化膜试样的极化曲线有明显的钝化区,点蚀电位为-13mV,去除氧化膜试样在盐雾腐蚀12h后表面有大范围的腐蚀区域,而含氧化膜试样盐雾腐蚀48h后才有大区域腐蚀发生.

Effect of oxide film on tribological properties at room temperature and corrosion performance of QPQ nitride layers on 14Cr12Ni2WMoVNb steel

This study analyzed the effects of the oxide film of 14Cr12Ni2WMoVNb steel with QPQ (quench-polish-quench) treatment on tribological properties at room temperature and corrosion resistance of the layers.The microstructure and properties of specimens with and without oxide film were studied by metallographic analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), a scratch tester, friction and wear tester, and at an electrochemical workstation.Results show that the effects of the oxide film on tribological properties of the layers are related to load.When the friction time is 4min and the load is low (50N), the friction coefficient of the oxide film and the volume wear rate are effectively decreased.However, with a friction time of 4min and a high load (100N), the oxide film is destroyed, there is thus no reduction in the volume wear rate.The study also shows that the oxide film obviously improves the corrosion resistance of the layers.The Tafel polarization curve of the specimen with oxide film has an obvious passivation region, and the pitting potential is-13mV.The surface of the specimen with the oxide film removed has a wide area of corrosion after salt spray corrosion for 12h, whereas a large area of corrosion only occurs after 48h of salt spray for the specimen with the oxide film.