When welding pipe equipment, there are often problems with seam opening. What is seam opening, which is the phenomenon of not being able to connect the seams together, resulting in substandard quality. Generally, the length of the seam is several centimeters or more, so what are the reasons for the seam opening of the welding pipe equipment? Today, Han Gao Machinery Welding Pipe Machinery will explain to you!

The primary cause of seam opening in welded pipe equipment is material issues, most of which are caused by the chemical composition of the raw materials. Although during the welding process, all factors are normal, and cracking occurs during the pipe sizing process, or we see that the crack in the weld is deviated from the center of the weld, and the irregular seam is formed by the bonding of the edge of the base material. This is purely a brittle crack phenomenon caused by the chemical composition of the raw materials!

Secondly, there are physical reasons - magnetic rods. Magnetic rods are the magnetic fields generated during the welding process of the tube blank, which can cause high-frequency currents to concentrate in the "V" shaped area of the weld seam, allowing the weld seam to reach a high temperature point in a very short time. The opening caused by magnetic rods has obvious characteristics, that is, the weld seam is black red, and there is no spark splashing. The weld seam is in a fully open shape, and sometimes, although it is welded, it belongs to false welding!

Next is the wear of the pass, accompanied by the wear of the extrusion roller pass, the (R) size of the pass gradually increases. When hot rolled steel strip is used as the raw material for welding pipes and there is a negative deviation or slight tension in the width of the steel strip, quality problems can occur in the weld seam, which can lead to sand hole pipes and no internal welding ribs, and in severe cases, it can result in slotted pipes. Therefore, it is necessary to regularly check the internal burrs of the welded pipe, increase the extrusion amount of the extrusion roller, or replace it with a new pass.

The final cause of cracking in the welded pipe equipment is bearing damage. During welding, although the bearings of the extrusion roller are slightly damaged, quality issues such as sand hole pipes and overlap welded pipes can occur. If the bearings are severely damaged, the extrusion pressure on the weld seam of the extrusion roller on the pipe blank will be lost, resulting in a fully open weld seam, which is accompanied by other quality accidents. At this point, we can also observe the squeezing roller with damaged bearings, and the swing amplitude will increase as the degree of bearing damage increases.