The groove of the squeeze roller is perforated and gradually becomes larger by the R dimension. When the use of pipe material hot-rolled strip, when there is a negative deviation or moderate strength of steel strip width, the weld will appear quality problems, the light occurs bubble tube, no internal weld reinforcement, heavy cut pipe. It is necessary to constantly check the state of the welding pipe and increase the squeeze squeeze the squeeze.
Despite the advantages of high precision
HFW steel pipe, but in contrast, straight seam submerged arc welded pipe welding performance is stable, high quality reliability. Spiral submerged arc welded pipe material performance advantage. The transverse yield strength of the pipe is to ensure that the bearing capacity of the pipe is the most important performance index. Spiral submerged arc welded pipe coil raw material sampling general requirements and welding pipe transverse direction, such as the West-East Gas Pipeline second-line demand and the rolling direction of the coil into 30 °. Straight seam steel pipe is not penetrated defect, that is, between the parents of metal or base metal and weld metal between the local incomplete fusion phenomenon. It is usually present in the unilateral weld seam root stress concentration sensitive, greater impact on strength, fatigue performance. The reason is: wire, electrode angle is not correct.
