1Cr18Ni9Ti 不锈钢表面电火花熔覆 WC 涂层特性研究

目的研究1Cr18Ni9Ti不锈钢经电火花强化后,WC涂层的显微组织和性能。方法采用电火花熔覆技术在不锈钢1Cr18Ni9Ti基体表面制备WC熔覆层,并分析熔覆层的表面形貌、显微组织、显微硬度、耐磨性,采用线性极化法研究熔覆层在3.5%(质量分数)Na Cl腐蚀溶液中的耐腐蚀性能。结果熔覆层组织均匀、连续、致密,与基体呈冶金结合。显微硬度最大值达到1680HV0.3,平均值为1336HV0.3,比不锈钢基材提高了4倍,耐磨性是不锈钢基材的4倍。在3.5%Na Cl腐蚀溶液中,熔覆层的自腐蚀电位较不锈钢减小了约165 m V,击破电位低于不锈钢基材,维钝电流密度高于不锈钢基材。结论熔覆层具有高硬度和高耐磨性能,磨损机理主要是粘着磨损和磨粒磨损,但在3.5%Na Cl腐蚀体系中,耐腐蚀性能低于1Cr18Ni9Ti不锈钢。

Characterization of Electro-spark Cladding WC Coating on Surface of 1Cr18Ni9Ti Stainless Steel

Objective To investigate the microstructure and properties of the WC coating on the surface of the 1Cr18Ni9Ti stainless steel prepared by electro-spark cladding technique. Methods The WC cladding coating was produced on the surface of stainless steel 1Cr18Ni9Ti by electro-spark cladding technique. The morphology, microstructure, microhardness and wear resistance of the cladding coating were investigated. The corrosion resistance of the cladding coating in 3. 5% NaCl solution was evaluated by linear polarization. Results The cladding coating was uniform, continuous, compact, and well metallurgically bonded with the substrate material. The highest microhardness was 1680HV0. 3 and the average hardness of the cladding coating was 1336HV0. 3, which was about 4 times higher than that of the substrate (260HV). The wear resistance of the cladding coating was 4 times as high as that of the substrate and the main wear mechanism was adhesive and abrasive wear. In the 3. 5% NaCl corroding liquor, the corrosion potential of the cladding coating moved reversely by 165 mV, and the breakdown potential of cladding coating was lower than that of the substrate, while the maintaining passive current density was higher than that of the substrate. Conclusion The cladding coating had high hardness and high wear resistance, and the main wear mechanism was adhesive and abrasive wear. However, in the 3. 5% NaCl corrosion system, the corrosion resistance of the1Cr18Ni9Ti stainless steel substrate was better than the cladding coating.