Casing connections in the oil and gas industry are typically coated with zinc and/or manganese phosphate for corrosion protection during storage. The presence of phosphate coatings is also known to give beneficial tribological performance. The coating allows the system to run without problems long after it is worn off. This is because of two mechanisms. Glaze layer formation on the coated surface and, as will be shown, tribofilm formation on the uncoated counter-surface. An investigation into the mechanism behind this tribofilm formation is presented in this paper. The aim is to develop lubricants that exploit these mechanisms. A pin-on-disc set-up was used to investigate the interaction of a manganese phosphated disc and bare counter surface. Six base oils with different polarity and viscosity were used. The resulting tribofilms were analysed using optical microscopy, scanning electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, focused ion beam, and atomic force microscopy. The tribofilm is robust, amorphous, and only forms in the presence of a lubricant under sliding conditions and adsorbs on substrates with a large variation in chemical composition. It is concluded that the tribofilm consists of physisorbed manganese phosphate and formation is shear stress activated.

中文翻译：

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磷酸锰转化膜摩擦膜吸附机理的表征。

石油和天然气工业中的套管连接处通常涂有锌和/或磷酸锰，以在存储过程中提供防腐蚀保护。还已知磷酸盐涂层的存在会产生有益的摩擦性能。涂层使系统在磨损后很长一段时间都可以正常运行。这是由于两种机制。如将显示的，在涂覆的表面上形成釉层，并且在未涂覆的相对表面上形成摩擦膜。本文介绍了摩擦膜形成背后的机制。目的是开发利用这些机理的润滑剂。盘上销钉设置用于研究磷酸锰化的光盘和裸露的对置表面之间的相互作用。使用了六种极性和粘度不同的基础油。使用光学显微镜，扫描电子显微镜，X射线衍射仪，X射线光电子能谱，聚焦离子束和原子力显微镜对所得的摩擦膜进行了分析。摩擦膜是坚固的，无定形的，并且仅在滑动条件下在润滑剂的存在下形成，并吸附在化学成分变化很大的基材上。结论是，摩擦膜由物理吸附的磷酸锰组成，其形成是剪切应力激活的。