Forming Process of High Frequency Straight Seam Welded Pipe (ERW)

The production process of high-frequency welded pipe depends primarily on the product variety, from raw materials to product requirements through a series of processes, to complete these processes requires a variety of corresponding mechanical equipment and welding, electrical control, testing equipment, these equipment and equipment in accordance with different processes The process requires multiple reasonable placements.

Typical process of high-frequency welded pipe: uncoiling-strip steel leveling-head and tail shear-strip steel butt welding-looper storage-forming-welding-burr removal-sizing-flaw detection-flying cutting-initial inspection-steel pipe straightening- Pipe processing-hydraulic test-flaw detection-printing and coating-products. High-frequency welding is a type of welding method that uses the resistance heat generated by the high-frequency current flowing through the continuous touch surface of the workpiece and applies upset force to complete the continuous metal between the workpieces.

High-frequency welded pipes are similar to general resistance welding, but there are many important differences. High frequency welding has been used in the production of carbon steel welded pipes for more than 40 years. High frequency welding has a large power supply, and can reach a higher welding speed for steel pipes of different raw materials, diameters and wall thicknesses (more than 10 times higher than the maximum welding speed of argon arc welding).

Therefore, high-frequency welding produces steel pipes that are generally used with higher yields. Due to the high speed of high-frequency welding, it is difficult to remove burrs in the welded pipe. This is also the current high-frequency welded steel pipe can not withstand the chemical industry and the nuclear industry. one of the reasons. From the perspective of welding materials, high-frequency welding can weld various types of steel pipes. Together, the development of new steel types and the advancement of forming welding methods.

The high frequency straight seam welded pipe does not require a particularly complicated production process, and its quality improvement is only based on the improvement of iron and steel smelting technology, hot rolled strip technology, and pipe making technology. After the high frequency straight seam welded pipe is formed, its welding The seam is very narrow. Therefore, this type of high-frequency straight seam welded pipe is often used for the transmission of liquids, gases, etc. The common high-frequency straight seam welded pipes in our daily life are domestic water supply pipes and gas pipes.

However, due to the structural characteristics, the high-frequency straight seam welded pipe has a small diameter, so it is often used as a threading pipe in construction sites. In buildings such as roads and bridges, metal threading pipe protection can not only protect the water and electricity pipes inside from being squeezed, corroded, etc., but also facilitate the repair of pipeline lines, greatly reducing the workload when the building lines are replaced. In addition, because of the high strength of the high-frequency straight seam welding control tube, it can sometimes play a role in stabilizing the building structure and strengthening the building foundation.

Of course, different uses of high-frequency straight seam welded pipes will also use different materials, or mix other elements in the raw materials. When it is used as a threading pipe, in order to delay the breakage time, it is often coated with a layer of zinc on its surface to improve the ability of anti-corrosion and anti-rust. Although the production process of high-frequency straight-seam welded pipe is simple, it is also subject to rigorous inspection before it can be used in engineering. Therefore, in all major manufacturing fields, high-frequency straight-seam welded pipe can also be favored.

In the field of oil and gas production and transportation, high frequency straight seam welded pipe (ERW steel pipe) is widely used for its advantages of low manufacturing cost, high dimensional accuracy, and easy control of fixed length. It is mainly used for onshore and offshore oil, natural gas, The transportation of ore pulp has broad application prospects. As the global demand for oil and natural gas continues to grow, the mining conditions for oil and natural gas wells are getting worse and more complex. Due to the successive development of some oil and gas fields with high H and S content and severely corrosive environments, there is an urgent need for the development and production of steel pipe manufacturing industry to adapt to the transportation of oil and natural gas under such acidic working conditions. At present, there are hundreds of high frequency straight seam welded pipe (ERW) units in China, but most manufacturers can only rely on large steel mills to provide coil raw materials, mainly producing conventional steel grade steel pipes. There is no corresponding domestic manufacturer for high-grade pipeline pipes with excellent HIC (hydrogen induced crack) performance that is urgently needed by the market. For HIC-resistant L360MCS steel grade high frequency straight seam welded pipe and its manufacturing process, there is still a gap in China.