Introduction Due to its high efficiency, low cost and good stability, ERW steel pipe occupies an important position in the market. However, the corrosion problem is a key factor affecting the service life and performance of ERW steel pipes. This paper will discuss the corrosion resistance of ERW steel pipes and its influencing factors in detail, aiming to provide a reference for research and application in related fields. Corrosion resistance of ERW steel pipe 1. Basic structure and manufacturing process of ERW steel pipe ERW steel pipe heats the edge of the steel strip by high-frequency current to make it melt, and then squeezes the molten edge together by a pressure roller to form a weld. Its manufacturing process mainly includes steel strip preparation, forming, welding, heat treatment and subsequent processing. Since the metallographic structure and mechanical properties of the weld zone are different from those of the parent material, its corrosion resistance will also be affected. 2. Corrosion resistance of ERW steel pipe The corrosion resistance of ERW steel pipe is mainly reflected in the following aspects: Difference in corrosion resistance between weld area and parent material: Due to high temperature melting and rapid cooling, intergranular corrosion and stress corrosion cracking may occur in the weld area, so the corrosion resistance of the weld area is often lower than that of the parent material. Surface treatment and coating protection: ERW steel pipes usually require surface treatment and coating protection to enhance their corrosion resistance. Common treatment methods include hot-dip galvanizing, epoxy resin coating, etc. Inner and outer wall corrosion: The inner and outer wall corrosion of ERW steel pipes are different. The inner wall is usually more affected by medium corrosion, while the outer wall is mainly affected by environmental factors. Factors affecting the corrosion resistance of ERW steel pipes 1. Material composition The chemical composition of the steel pipe directly affects its corrosion resistance. Changes in trace elements such as carbon content, sulfur content, and phosphorus content will affect the corrosion resistance of steel. For example, the corrosion resistance of low carbon steel is generally better than that of high carbon steel, while high sulfur and high phosphorus steels are prone to intergranular corrosion. 2. Welding process Welding process parameters (such as current, voltage, welding speed, etc.) have an important influence on the metallographic structure and performance of the weld area. If the welding process is not properly controlled, defects such as pores and cracks may occur, which will become the starting point of corrosion. 3. Heat treatment Post-weld heat treatment is very important for optimizing the performance of the weld area. Reasonable heat treatment can eliminate welding residual stress, refine grains, and improve the corrosion resistance of the weld area. Common heat treatment methods include annealing, tempering, etc. 4. Surface treatment The surface treatment of ERW steel pipe has a significant effect on its corrosion resistance. Surface treatment methods such as hot-dip galvanizing and epoxy resin spraying can form a protective layer on the surface of the steel pipe to prevent the corrosive medium from directly contacting the steel, thereby improving the corrosion resistance. 5. Use environment The medium type, temperature, humidity and other factors of the use environment have a direct impact on the corrosion resistance of ERW steel pipes. For example, in an acidic, alkaline or salt spray environment, the corrosion rate of the steel pipe will be significantly accelerated. Therefore, when selecting ERW steel pipes, it is necessary to consider their use environment and take corresponding anti-corrosion measures. Corrosion resistance improvement measures for ERW steel pipes 1. Material optimization By optimizing the chemical composition of steel, such as reducing the carbon, sulfur, and phosphorus content, and increasing alloying elements (such as chromium, nickel, etc.), the corrosion resistance of steel can be significantly improved. In addition, the use of high-quality raw materials and reducing the impurity content can also help improve corrosion resistance. 2. Process improvement Improving the welding process and using advanced welding equipment and control technology can reduce welding defects, optimize the metallographic structure of the weld area, and improve corrosion resistance. For example, using automated high-frequency welding equipment to accurately control welding parameters and reduce the influence of human factors. 3. Heat treatment optimization Reasonable selection and control of heat treatment processes can eliminate welding stress, refine grains, and improve corrosion resistance. For example, annealing after welding can effectively eliminate welding stress and prevent the occurrence of intergranular corrosion. 4. Surface treatment and protection The use of efficient surface treatment methods, such as hot-dip galvanizing and epoxy resin spraying, can form a solid protective layer on the surface of the steel pipe to improve its corrosion resistance. In addition, regular inspection and maintenance of steel pipes, timely detection and treatment of corrosion problems, can also help to extend its service life. 5. Environmental protection When using ERW steel pipes, they should be avoided from being exposed to harsh environments as much as possible. For example, when used in a marine environment, measures such as cathodic protection and corrosion inhibitors can be used to reduce the impact of corrosive media. In addition, reasonable design and layout of pipelines to reduce the presence of corrosion factors such as stagnant water and mud can also help improve corrosion resistance. Conclusion The wide application of ERW steel pipes in various industries makes the study of its corrosion resistance of great significance. Through a comprehensive analysis of factors such as material composition, welding process, heat treatment, surface treatment and use environment, the corrosion resistance of ERW steel pipes can be effectively improved. Future research should continue to focus on the application of new materials and new processes, as well as in-depth research on corrosion mechanisms, to provide more reliable technical support for the application of ERW steel pipes. To learn more, please visit the website: https://www.baowi-steel.com