Preventive measures for welded pipe cracking

Posted by chase Liu on June 6th, 2023

The welded pipe is a steel pipe made of steel plate or strip steel after being crimped and welded, 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. A large number of pipelines used to transport fluids, such as octg casing, natural gas, gas, water and certain solid material pipelines, etc.

In daily work and production, welded pipes stored for a long time should be inspected regularly, and the surface of welded pipes exposed outside must be kept clean, cleaned of dirt, and stored neatly in a ventilated and dry place indoors. It is strictly forbidden to stack them in open air or damp places. Always keep the welded pipe dry and ventilated, keep it clean and tidy, and store it according to the correct storage method.

When installing, the welded pipe can be directly welded on the pipeline according to the connection method, and installed according to the position used. Under normal circumstances, it can be installed at any position in the pipeline, but it needs to be easy to operate and inspect, pay attention to the flow direction of the stainless steel welded pipe medium, and the stainless steel welded pipe should be installed horizontally or vertically. Pay attention to the tightness of the welded pipe during installation to prevent leakage and affect the normal operation of the pipeline.

Going back to the processing of welded pipes, bending and stretching is a procedure for deep processing of welded pipes. In this process, weld cracking is easy to occur and a large amount of waste products are generated. In order to prevent similar problems from happening, it is necessary to use appropriate lubricants to have a significant effect on the drawing and bending of welded pipes.

Because the lubricant can form a film with a certain toughness and elongation between the convex and concave dies, it is beneficial to the deep drawing and bending of the welded pipe. For welded pipe drawing parts with large degree of deep drawing deformation and difficult bending and forming, polyvinyl fluoride film can be used as lubricant in actual production. Polyvinyl fluoride film has excellent tear strength, certain toughness and elongation and is easy to clean.

After coating the dry film, the dry film can be deformed together with the blank during the drawing process, which can always separate the blank from the mold. In addition, the film itself has a certain porosity and a large number of fiber cracks, so it can also store a certain amount of lubricating oil, so the film is equivalent to a layer of dry film lubricant. This lubrication method can effectively isolate the deformed welded pipe from the surface of the mold, and the lubrication effect is good, which is conducive to improving the service life of the mold and the pass rate of the finished product.