Ni-WC涂层在饱和H2S溶液中的磨损和腐蚀行为

为了提高深海石油钻采工具的耐磨耐蚀性能，利用等离子转移弧堆焊(PTA)在不锈钢表面制备了不同球形碳化钨(WC)含量的镍(Ni)基涂层，并研究了该涂层在饱和硫化氢(H₂S)溶液中的耐磨损与腐蚀性能。通过X射线衍射仪、扫描电子显微镜、X射线光电子能谱仪等方法研究了涂层的表界面形貌和组成结构。利用显微硬度测试仪和摩擦磨损测试仪研究了涂层的耐磨损性能。通过极化曲线和3D光学轮廓仪等方法研究了涂层在H₂S溶液中的腐蚀速率和点蚀分布。结果显示，球形WC粉末的Ni基合金颗粒经过离子转移电弧堆焊在合金钢表面形成的涂层，其主要成分为WC，W₂C，Ni和Ni₃Fe。但WC的体积分数对于涂层的耐磨耐蚀性能影响较大，当WC的体积分数为60%时(Ni-60%WC)，涂层在H₂S溶液中的耐磨与耐蚀性能均优于单纯的Ni基涂层和Ni-30%WC涂层。因此，文中研究为深海石油钻采工具的表面防护提供了一种新的思路和选择。

Wear and Corrosion Behaviour of Ni-WC Coatings in Sulfuretted Hydrogen Medium

To improve the abrasion and corrosion resistance of deep-sea oil drilling tools, in this study, Ni-based coating containing different content of WC particles were coated on the stainless steel by plasma transferred arc (PTA). The abrasion and corrosion behaviors of the coating were studied in the saturated sulfuretted hydrogen medium. The morphology and composition of the coating were characterized by X-ray diffraction, scanning electron microscopy with an energy dispersive spectrometer, X-ray photoelectron spectroscopy. Micro-hardness test, friction and wear test were taken to value the hardness and wear resistance. Corrosion resistance and pitting distribution of the coating were studied by the potentiodynamic polarization and 3D optical profilometer. Results show that the Ni-WC coating, which is prepared by PTA process, is consisted of WC, W₂C, Ni and Ni₃Fe. However, the volume fraction of WC has a great influence on the abrasion and corrosion resistance of the coating. When the volume fraction of WC is 60%, Ni-60% WC coating exhibites higher wear and corrosion resistance in H₂S medium compared with the other groups (Ni alloy coating and Ni-30% WC). Therefore, it introduces a new perspective and an option for abrasion and corrosion control in deep-sea oil drilling environment.