Study On Corrosion Resistance Properties Of Water-lubricated Bearing Materials

In recent years, precious metals, oil and other strategic resources increasingly become scarce, the human survival environment is deteriorating. Based on resource saving and environmentally friendly mechanical design, manufacturing theory, methods and techniques, get more and more attention from governments and scholars all over the world. Lubricant is indispensable for most mechanical equipment normal operation. However, the widespread use of lubricants not only caused serious environmental pollution, but also wasted a lot of oil resources and labor costs. Water instead of mineral oil as a lubricated medium has been the leading subject which is concerned and researched by many scholars. The main advantages of water lubrication include pollution-free, wide source and low cost. To the water lubricated theory and application of water lubricated bearings, how to better improve the friction and wear characteristic of water lubricated bearings and how to solve the corrosive problems of metallic materials in the water environment are the projects which must be addressed.In the water environment and other environments with different pH, corrosive properties of some commonly used water lubricated bearing materials and component materials are first systematically studied in this article. The corrosive mechanism is analyzed, and a lot of anticorrosive methods are proposed. In addition, those anticorrosive methods are verified by experiments and analyzed. Through this study, some important conclusions about corrosive and anticorrosive features of water lubricated friction materials are proposed which provide an experimental basis for the selection and application of water lubricated bearing materials.1,Under the same experimental conditions, in four different kinds of media, the corrosion resistance of the same materials shows great differences. Acidity or basicity of the solution has a great influence on the corrosion of metallic materials. Among these, the metals are corroded most obvious in 5% hydrochloric acid solution. In addition to stainless steel, the metals have a lower corrosion in the alkaline solution. 2,The corrosion resistance of different metallic materials varies greatly. In pure water, the corrosion resistance of stainless steel is better, and it is suitable material for water lubricated bearings; Cast iron and Babbitt show poor corrosion resistance, and the anticorrosive measures must be taken before being used.3,In pure water, the corrosive mechanism of metal is classed for oxygen-consuming corrosion in the electrochemical corrosion. Oxygen in the air is the external factor leading to the electrochemical corrosion. But the high potential of carbon existence in the metals is the internal factor leading to the metallic corrosion. Because the ingredients are different in different metals, their corrosion resistance properties are also different. The more active metal contained in alloy or the greater potential difference between the different components, the easier to electrochemical corrosion.4,Using sacrificial anode method, impressed current method, removing oxygen method and galvanized method, for improving the corrosion resistance of the metallic materials in water environment, are obviously effective. Among them, the best anticorrosive method is the impressed current method.