advantages of casting advantages and disadvantages of longitudinal submerged arc ...

First, the advantages of longitudinal submerged arc welding can destroy the ingot casting structure, refine the grain size of the steel, eliminate the defects of the structure, and thus make the steel structure...First, the advantages of longitudinal submerged arc welding can damage the ingot casting structure, refine the grain size of the steel, eliminate the defects of the structure, make the steel structure compact and improve the mechanical performance.This improvement is mainly reflected in the rolling direction, so that the straight-seam steel pipe is no longer of the same sex to a certain extent;Bubbles, cracks and looseness will be formed during pouring, and will also be welded under high temperature and high pressure.Two: Defects of straight seam submerged arc welded steel pipe 1. Residual stress caused by uneven cooling.The residual stress is in the case of no external force, the internal self-Balance stress, Crosssection of hot-Steel has such residual stress, the general steel crossAlthough the residual stress is self-stress, the larger the section size, the greater the residual stressBalance, it has certain influence on the performance of steel members under the action of external force, such as deformation, stability, fatigue resistance, etc., which may have adverse effects.2. after weldingThe metal inclusion inside the straight-seam steel pipe is pressed into the sheet, resulting in layering.The performance of the straight-seam steel pipe in the thickness direction is greatly deteriorated. when it is possible to weld, the local strain caused by welding shrinkage often reaches several times the yield point strain, which is much larger than the load caused by the load.