熔盐渗硅对G3镍基合金表面耐磨及耐蚀性能的影响  

Effect of siliconizing in molten salt on wear and corrosion resistance of G3 nickel-based alloy

作　　者：文芙蓉 唐长斌[1] 陈红霞 许妮君[1] 薛娟琴[1] 赵亮 WEN Fu-rong;TANG Chang-bin;CHEN Hong-xia;XU Ni-jun;XUE Juan-qin;ZHAO Liang(College of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]西北工业集团计量理化二中心,陕西西安710043

出　　处：《电镀与涂饰》2018年第21期994-998,共5页Electroplating & Finishing

基　　金：国家自然科学基金(51501138)

摘　　要：以G3镍基耐蚀合金为基材,在含有Na2Si F6和Si粉的Na Cl–KCl–Na F熔盐中通过非电解的方式获得10μm左右的渗硅层。采用X射线衍射仪(XRD)、扫描电镜(SEM)和显微硬度计分析了渗硅层的物相、微观结构和硬度分布。借助摩擦磨损试验机,以GCr15钢球作配副,对比研究了G3合金基材及其表面渗硅层的球-盘磨损行为。通过极化曲线和电化学阻抗谱测量,评价了渗硅层在体积分数为10%的H2SO_4水溶液中的耐蚀性能。结果表明:所得合金化金属间硅化物渗层与G3基体结合牢固,均匀、连续、致密,表面硬度比基体高2倍。渗硅层的化学组成及硬度的梯度分布有助于提高耐磨性,其体积磨损量降低至基材的1/7。渗硅层在10%硫酸溶液中具有明显的二次钝化特性,但会使G3合金基材的耐蚀性稍有降低。A siliconized layer of ca.10μm in thickness was prepared non-electrolytically on the surface of G3 Ni-based corrosion-resistant alloy in a NaCl–KCl–NaF molten salt containing Na2SiF6 and Si particles,and its phase composition,microstructure,and microhardness distribution of were analyzed using X-ray diffractometer(XRD),scanning electron microscope(SEM),and microhardness tester.The wear behaviors of G3 alloy and the siliconized layer on it against a GCr15 steel ball were comparatively studied using a ball-on-disc tribometer.The corrosion resistance of the siliconized layer in aqueous 10vol.%H2SO4 solution was evaluated by polarization curve measurement and electrochemical impedance spectroscopy.The results showed that the siliconized layer was uniform,continuous,compact,composed of alloyed intermetallic silicides,and well adhered to the substrate with a surface hardness two times higher than the substrate.The existence of composition and hardness gradients in the siliconized layer enhanced its wear resistance.The volume loss of the siliconized layer was reduced to 1/7 of that of the substrate after friction wear test.The siliconized layer showed an obvious repassivation behavior in 10vol.%H2SO4 solution,but slightly reduced the corrosion resistance of the G3 alloy substrate.

关 键 词：镍基合金 熔盐渗硅 微观结构 显微硬度 摩擦磨损 耐蚀性 

分 类 号：TG156.83[金属学及工艺—热处理]