Petroleum machinery castings play an important role in the petroleum industry, however, because its working environment is usually highly corrosive and high wear, so the surface treatment of castings is of great significance to improve its corrosion resistance and wear resistance. This paper will discuss the surface treatment technology and process of petroleum machinery castings.
The surface treatment of petroleum machinery castings is designed to improve its corrosion resistance, wear resistance, fatigue resistance and aesthetics, thereby extending its service life, reducing maintenance costs and improving the overall performance of the equipment. Through surface treatment, the physical and chemical properties of the casting surface can be changed, the surface hardness and corrosion resistance can be improved, and the fatigue resistance and wear resistance can be enhanced.
Surface treatment technology and technology
Shot peening: Shot peening is a kind of surface treatment method that jets the projectile to the surface of the casting through high-speed air flow to produce plastic deformation and stress layer on the surface, so as to improve its fatigue strength and wear resistance. The shot peening process is simple and suitable for castings of various shapes and sizes.
Carburizing quenching: Carburizing quenching is a process method of heating and holding low carbon steel or low carbon alloy steel in carburizing medium, so that carbon atoms penetrate into the surface layer, obtain a high carbon layer, and then quenching to obtain a high hardness surface layer. Carburizing and quenching can improve the wear resistance and fatigue resistance of castings, but the process is complicated and the cost is high.
Spraying technology: Spraying technology is a method of coating a metal or non-metal material on the surface of the casting to form a protective layer. Commonly used spraying materials include zinc, aluminum, chromium, nickel and other metals and their alloys, as well as non-metallic materials such as plastics and ceramics. Spraying technology can improve the corrosion resistance, wear resistance and aesthetics of castings.
Electroplating: Electroplating is a process that uses the principle of electrolysis to deposit metal or alloy coating on the surface of castings. Electroplating can improve the corrosion resistance and aesthetics of castings, but the coating is easy to peel off and the corrosion resistance is limited.
Thermal spraying: Thermal spraying is a process that uses a heat source to heat a metal or non-metallic material to a molten or semi-molten state, and then sprays it to the surface of the casting at high speed to form a coating. Thermal spraying can improve the corrosion resistance, wear resistance and fatigue resistance of castings, but the process is complicated and the cost is high.
Conversion film treatment: Conversion film treatment is a process method to form a layer of metal compound film with strong adhesion on the metal surface by chemical or electrochemical methods. Conversion film treatment can improve the corrosion resistance and beauty of castings, and has better wear resistance.
When selecting and applying surface treatment technology, it should be comprehensively considered according to the use environment and working conditions of the casting. For highly corrosive and high-wear working environments, surface treatment technologies with high corrosion resistance and high wear resistance should be selected, such as shot peening, carburizing and quenching, spraying technology, etc. For the general working environment, you can choose simple surface treatment technology such as electroplating and thermal spraying. At the same time, the cost and operability of surface treatment technology should also be considered.
The surface treatment of petroleum machinery castings plays an important role in improving its corrosion resistance, wear resistance, fatigue resistance and aesthetics. When selecting and applying surface treatment technology, the appropriate surface treatment technology and process should be selected according to the actual working conditions and use environment, so as to improve the overall performance and service life of the casting.
