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Surface Treatment Of Steel Pipes

Steel pipe surface treatment method, the state vigorously develop the energy industry, with the continuous development of China's economy. Oil and gas pipeline is an important way to ensure the energy, oil (gas) pipeline anticorrosion construction process, the steel surface treatment is one of the key factors determining the service life of the pipeline anticorrosion coating and steel pipe, the premise can firmly combine. The service life of anticorrosive coating depends on the coating type, coating quality and construction environment. The influence of the surface disposal of steel pipe on the life of anticorrosive coating accounts for about 50%. Therefore, the requirements of steel pipe surface should be strictly followed according to the anticorrosion layer code. From time to time, the steel pipe surface treatment method can be improved from time to time.

1 cleaning to remove oil, grease, dust, lubricants and similar organic compounds, using solvent and emulsion to clean the surface of steel. But it can't remove the rust, welding of steel surface oxide skin, etc. Therefore, in coating production only as a supplementary means.

2 tool derusting steel pipe surface treatment method can remove loose or tilted oxide skin, rust, welding slag and so on. Manual tool derusting can reach Sa2 level, mainly using steel wire brush and other tools to polish the surface of steel. The rust removal of power tools can reach Sa3 grade. If the iron oxide scale is adhered on the steel surface, the rust removal effect of the tool is not ideal, and the anchorage depth can not meet the requirements of corrosion protection construction.

3 acid pickling pipeline only uses chemical pickling, which is usually treated by chemical and electrolytic methods in two ways.  It can remove the oxide scale, rust, old coating, and sometimes can be used as sand blasting rust removal after treatment.  Although the chemical cleaning can make the surface reach a certain degree of cleanliness and roughness, but the anchor is shallow, and easy to pollute the environment.

4 spray (CAST) steel grit, steel shot, the shot derusting wire section, minerals and other abrasive spraying on the surface of the steel pipe under the action of centrifugal force (left) injection treatment, spray (toss) shot derusting by the high-power motor driven jet shot (impeller) blade to rotate in high speed. Not only the rust, oxide and dirt can be completely removed, but also the uniform roughness of the steel pipe can be achieved under the impact of the abrasive and the friction force. The surface treatment method of steel pipe can not only enlarge the physical adsorption of pipe surface, but also spray (throwing) and rust removing. It can also enhance the mechanical adhesion between the anti-corrosion layer and the pipe surface. Therefore, spraying (throwing) is an ideal rust removal method for pipeline corrosion protection. Generally speaking, shot peening (sand) rust removal is mainly used for inner surface treatment of tubes, shot blasting (sand) rust removal is mainly used for outer surface treatment of tubes.