Welded steel tube, also known as welded pipe, is a steel pipe made of steel plate or strip steel after crimping and welding, generally with a length of 6 meters. The production process of welded steel pipe is simple, the production efficiency is high, there are many varieties and specifications, and the investment in equipment is small, but the general strength is lower than that of seamless pipe.

Welding method of welded pipe:

The welding methods of welded pipes mainly include gas tungsten arc welding, flux cored arc welding, electrode arc welding, submerged arc welding, down welding and other methods.

Things to pay attention to during the welding process of welded pipes:

1. When welding steel pipes, it is necessary to use according to the purpose. Pay attention to the problem of shrinkage cracks during the welding process. For the mechanical properties of the pipes in the heat-affected zone, there should be no excessive changes due to the influence of welding operations.

2. Pay attention to the wall thickness of the welded pipe. If the wall thickness of the steel pipe is relatively thin, high frequency welding can be used. For some thin-walled steel pipes, protective gas welding can be used. If the wall thickness is relatively thick, manual arc welding can be used.

3. Weld according to the size of the pipe. If the welded pipe is relatively small and can only be welded through one side, it can be drilled into the pipe for welding. However, if one side is welded, the steel ball test must be passed, so as to ensure that the cross-sectional area meets the design requirements of weld forming.

4. If the steel pipe is a high-strength alloy steel with good wear resistance, temperature resistance, and pressure resistance, the welding process must be implemented to avoid cracking tendencies due to high-temperature welding operations.

5. When welding steel pipes, the welding swing should be minimized, and the arrangement of the welds should have an annealing effect on the heat-affected zone as much as possible. It can be cooled slowly after welding, and then covered with asbestos cloth.

Welded pipes are widely used in water supply engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, urban construction, etc. Compared with the welded pipe, the maximum diameter of the seamless pipe sizes can reach 650mm, and the minimum diameter is 0.3mm.