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Forming process of welded steel pipe

Time : 2021-05-11 Hits : 44

The development of steel pipe production technology began with the rise of the bicycle manufacturing industry, the development of petroleum 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 Second World War, the development of the chemical industry, and the development of the chemical industry. The drilling, production and transportation of oil and natural gas have strongly promoted the development of the steel pipe industry in terms of variety, output and quality. Generally, steel pipes are divided into two types: seamless steel pipes and welded steel pipes according to the production method. This time, we will mainly introduce welded steel pipes.


Welded steel pipes are seam steel pipes, which are produced by bending the tube billet (steel plate and steel strip) into a tube of the required cross-sectional shape and size by various forming methods, and then welding the welds by different welding methods. The process of obtaining steel pipes. Compared with seamless steel pipes, welded pipes have high product accuracy, especially wall thickness accuracy, simple main equipment, small footprint, continuous operation in production, flexible production, and wide product range of the unit.


The welded pipe should be divided from the production process, which is divided into:

1). SSAW (Spirally Submerged Arc Welding);

2). LSAW (Longitudinally Submerged Arc Welding);

3). There are three types of ERW (Electric Resistance Welding).



The production process of spiral steel pipe (SSAW) is roughly as follows:

The raw materials of spiral steel pipe (SSAW) are strip coil, welding wire and flux. Before forming, the strip undergoes leveling, edge trimming, edge planing, surface cleaning and conveying and pre-flanging treatment. The weld gap control device is used to ensure that the weld gap meets the welding requirements. It is required to strictly control the pipe diameter, the amount of misalignment and the gap between the welds. After cutting into a single steel pipe, the first three of each batch of steel pipes must undergo a strict initial inspection system to check the mechanical properties, chemical composition, fusion state and surface of the weld. Quality and non-destructive inspections to ensure that the pipe-making process is qualified can it be officially put into production.

Longitudinal submerged arc welded pipe (LSAW):

Generally speaking, LSAW steel pipes are made of steel plate as raw material. After different forming processes, double-sided submerged arc welding and post-weld diameter expansion are adopted to form welded pipes. LSAW pipes are formed by UO (UOE). , RB (RBE), JCO (JCOE), etc.


UOE longitudinal submerged arc welded pipe forming process:

UOE LSAW steel pipe forming process mainly has three forming processes: steel plate pre-bending, U forming and O forming. Each process uses a special forming press to complete the edge pre-bending, U forming and O forming of the steel plate in sequence. Three processes, the steel plate is deformed into a round tube, the JCOE LSAW pipe forming process: After multiple stamping on the JC0 forming machine, first half of the steel plate is pressed into a J shape, and then the other half of the steel plate is pressed into a J Shape, forming a C-shape, press from the middle to form an open "O"-shaped tube.


3. Straight seam high frequency welded pipe (ERW):

Straight seam high-frequency welded pipe (ERW welded pipe) is formed by forming a hot-rolled coil through a forming machine, using the skin effect and proximity effect of high-frequency current to heat and melt the edge of the pipe blank, and pressure welding is performed under the action of a squeeze roller. .

The above has introduced you to the relevant content of the three processes of welded pipe, and I hope that the above content will be helpful to you.

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