Since straight seam steel pipe is inseparable from human life and production activities, the production technology of straight seam steel pipe industry not only develops rapidly but also innovates. The production of straight seam steel pipe occupies an irreplaceable position in the iron and steel industry. The development of straight seam steel pipe production technology began in the construction manufacturing industry. The development of oil in the early 19th century, the manufacture of ships, boilers, and aircraft during the two world wars, the manufacture of thermal power boilers after the First World War, the development of the chemical industry, and the drilling and transportation of petroleum gas all strongly promoted the direct The development of seam steel pipe industry in terms of variety, output, and technology.
Straight seam steel pipe de-rusting method:
1. Cleaning: Solvents and emulsions clean the steel surface to remove oil, grease, dust, lubricants, and similar organic matter, but they cannot remove rust, oxygen-reactive skin, welding flux, etc. on the steel surface, so it is only used in defense operations as an aid.
2. Pickling: Chemical and electrolytic methods are used for pickling treatment. Only chemical pickling is used for pipeline anti-corrosion, which can remove oxygen-reactive skin, rust, and old coatings. Sometimes it can be used as retreatment after sandblasting and rust removal. Although chemical cleaning can achieve the cleanliness and roughness of the surface, its anchor pattern is shallow and it is easy to pollute the surrounding environment.
3. Rust removal with tools: Use wire brushes and other tools to polish the steel surface to remove loose oxygen-reactive skin, rust, welding slag, etc. Hand tool de-rusting can reach the Sa2 level, and power tool de-rusting can reach the Sa3 level. If the steel surface is attached to a firm oxygen-reactive iron sheet, the de-rusting effect of the tool is not ideal, and the anchor pattern depth required for anti-corrosion construction cannot be reached.
4. Spray rust removal: Rust removal is driven by a high-power motor to rotate the spray blades at high speed, so that steel shot, steel sand, iron wire segment, minerals, and other abrasives are sprayed on the surface of the straight seam steel pipe under the powerful centrifugal force of the motor, not only Oxygen reactants, rust and dirt can be eliminated, and the straight seam steel pipe can still achieve the required uniform roughness under the action of violent impact and friction of abrasives. After dusting by spraying, not only the physical adsorption on the surface of the pipe can be expanded, but also the mechanical adhesion between the anti-corrosion layer and the surface of the pipe can be enhanced. Therefore, spray rust removal is an ideal rust removal method for pipeline corrosion. Generally speaking, shot blasting is mainly used for the inner surface treatment of pipes, and shot blasting is mainly used for the outer surface treatment of straight seam steel pipes.
Straight seam steel pipe inspection steps:
1. Straight seam steel pipes should be submitted for acceptance in batches, and the batching rules should comply with the provisions of the corresponding product standards.
2. The inspection items, sampling quantity, sampling location, and test method of straight seam steel pipe shall be by the provisions of the corresponding product standards. With the consent of the purchaser, hot-rolled seamless straight seam steel pipes can be sampled in batches according to the number of rolling roots.
3. In the test results of straight seam steel pipes, if a certain item does not meet the requirements of the product standard, the unqualified ones should be picked out, and double the number of samples should be randomly taken from the same batch of straight seam steel pipes for inspection of unqualified items. recheck. If the re-inspection result (including any index required by the project test) is unqualified, the batch of straight seam steel pipes shall not be delivered. For the following inspection items, if the initial inspection fails, re-inspection is not allowed:
1) There are white spots in the low-magnification tissue;
2) Microstructure.
4. For the straight seam steel pipes whose re-inspection results are unqualified (including the unqualified microstructure of the initial inspection results, and items that are not allowed to be re-inspected), the supplier can submit them for acceptance one by one; or re-heat treatment (the number of re-heat treatments shall not exceed two times) ), to submit a new batch for acceptance.
5. If there is no special regulation in the product standard, the chemical composition of the straight seam steel pipe shall be checked and accepted according to the melting composition.
There are often two options for straight seam steel pipes in industrial production. One option is to use ordinary straight seam steel pipes, and the other is straight seam steel pipes with excellent performance. In the process of long-term production practice, enterprises have generally formed a consensus that this kind of straight seam steel pipe with multiple characteristics is superior to ordinary straight seam steel pipe in many aspects. The reason why this kind of straight seam steel pipe is slightly better than ordinary straight seam steel pipe is that this kind of straight seam steel pipe has several characteristics that ordinary straight seam steel pipe does not have.
One of the characteristics refers to the high abrasion resistance of this straight seam steel pipe itself. Straight seam steel pipes in pipeline transportation often need to bear a lot of friction. During the process of pipeline transportation, when materials pass through the pipeline, friction will often be generated at the elbow, especially when using pipelines to transport solid materials. At that time, the impact and friction of the pipe in the place of the straight seam steel pipe will probably cause great damage to the straight seam steel pipe.
Post time: Aug-18-2023