With the continuous development of our country's economy, the state is vigorously developing the energy industry. Long-distance oil and gas pipelines are an important means of energy security.Steel pipeSurface treatment is one of the key factors determining the service life of pipeline anti-corrosion. It is a prerequisite for the anti-corrosion layer to bond firmly.Steel pipeResearch institutions have verified that the lifespan of the anti-corrosion layer depends not only on factors such as coating type, coating quality, and construction environment but also that surface treatment accounts for about 50% of its lifespan.Steel pipeTherefore, it is necessary to strictly follow the requirements for surface treatment according to anti-corrosion layer specifications, continuously explore and summarize, and constantly improveSteel pipesurface treatment methods.Steel pipe表面处理方法。 1. Cleaning Using solvents and emulsions to clean the steel surface to remove oil, grease, dust, lubricants, and similar organic substances; however, it cannot remove rust, oxide scale, welding slag, etc., from the steel surface. Therefore, it is only used as an auxiliary means in anti-corrosion production. 2. Tool Rust Removal Mainly using tools such as wire brushes to grind the steel surface can remove loose or raised oxide scale, rust, welding slag, etc. Manual tool rust removal can achieve Sa2 level; power tool rust removal can reach Sa3 level. If there is firmly attached iron oxide on the steel surface, tool rust removal may not be ideal and may not meet the required anchor pattern depth for anti-corrosion construction.Steel pipe(My website www.wdggw.com) 3. Acid Pickling Generally using chemical and electrolytic methods for acid pickling treatment; pipeline anti-corrosion only uses chemical acid pickling which can remove oxide scale, rust, old coatings; sometimes it can be used as a re-treatment after sandblasting. Although chemical cleaning can achieve a certain level of cleanliness and roughness on surfaces, its anchor pattern is shallow and it easily causes environmental pollution. 4. Shot (Blast) Rust Removal (Shot) blasting rust removal involves driving shot (blast) blades at high speed with a high-power motor so that abrasives like steel shot or sand are propelled againstSteel pipe(the surface), which not only thoroughly removes rust, oxides and dirt but also achieves the desired uniform roughness under strong impact and friction from abrasives.Steel pipe在磨料猛烈冲击和磨擦力的作用下，还能达到所需要的均匀粗糙度。 (Shot) blasting not only expands physical adsorption on pipe surfaces but also enhances mechanical adhesion between the anti-corrosion layer and pipe surfaces. Therefore, shot (blast) rust removal is an ideal method for pipeline anti-corrosion. Generally speaking, shot peening (sand) rust removal is mainly used for internal surface treatment while shot blasting (sand) rust removal is primarily used for external surface treatment. There are several issues to pay attention to when using shot (blast) rust removal. Steel pipe常用的环氧类、乙烯类、酚醛类等防腐涂料的施工工艺，一般要求Steel pipe表面达到近白级(Sa2.5)。实践证明，采用这种除锈等级几乎可以除掉所有的氧化皮、锈和其他污物，锚纹深度达到40~100μm，充分满足防腐层与Steel pipe的附着力要求，而喷(抛)射除锈工艺可用较低的运行费用和稳定可靠的质量达到近白级(Sa2.5)技术条件。 Steel pipe表面的硬度、原始锈蚀程度、要求的表面粗糙度、涂层类型等来选择磨料，对于单层环氧、二层或三层聚乙烯涂层，采用钢砂和钢丸的混合磨料更易达到理想的除锈效果。钢丸有强化钢表面的作用，而钢砂则有刻蚀钢表面的作用。钢砂和钢丸的混合磨料(通常钢丸的硬度为40～50HRC，钢砂的硬度为50～60HRC可用于各种钢表面，即使是用在C级和D级锈蚀的钢表面上，除锈效果也很好。 为获得较好的均匀清洁度和粗糙度分布，磨料的粒径及配比设计相当重要。粗糙度太大易造成防腐层在锚纹尖峰处变薄;同时由于锚纹太深，在防腐过程中防腐层易形成气泡，严重影响防腐层的性能。 粗糙度太小会造成防腐层附着力及耐冲击强度下降。对于严重的内部点蚀，不能仅靠大颗粒磨料高强度冲击，还必须靠小颗粒打磨掉腐蚀产物来达到清理效果，同时合理的配比设计不仅可减缓磨料对管道及喷嘴(叶片)的磨损，而且磨料的利用率也可大大提高。通常，钢丸的粒径为0.8～1.3mm，钢砂粒径为0.4～1.0mm，其中以0.5～1.0mm为主要成分。砂丸比一般为5～8。 应该注意的是在实际操作中，磨料中钢砂和钢丸的理想比例很难达到，原因是硬而易碎的钢砂比钢丸的破碎率高。为此，在操作中应不断抽样检测混合磨料，根据粒径分布情况，向除锈机中掺入新磨料，而且掺人的新磨料中，钢砂的数量要占主要的。 4.4除锈速度 式中：m——磨料的喷(抛)量; V——磨料运行速度; m1——单颗粒磨料的质量。 The size of m is related to the abrasive fracture rate, and the size of the fracture rate directly affects the cost of surface treatment operations and the expenses for rust removal equipment. When the equipment remains fixed, m is a constant, y is a constant, so E is also a constant. However, due to abrasive fracture, m1 changes. Therefore, generally, abrasives with lower loss rates should be selected, which is beneficial for improving cleaning speed and extending the lifespan of long blades. 4.5 Cleaning and Preheating Before spraying (throwing) treatment, use cleaning methods to removeSteel pipesurface grease and dirt, and use a heating furnace to preheat the pipe body to 40-60°C to keepSteel pipethe surface dry. During spraying (throwing) treatment, sinceSteel pipethe surface does not contain grease or other dirt, it can enhance the rust removal effect. A drySteel pipesurface also facilitates the separation of steel shots or steel sand from rust and oxide scale, making the surface of the cleanedsteelpipemore clean. | 
