The advantages and disadvantages of lsaw pipe

Advantages of lsaw pipe
It can destroy the casting structure of the steel ingot, refine the grain of the steel, and eliminate the defects of the microstructure so that the steel structure is dense and the mechanical property is improved. This improvement is mainly reflected in the rolling direction so that the lsaw pipe to some extent is no longer isotropic body; pouring bubbles, cracks and loose formation, but also can be welded under high temperature and pressure.

Defects of lsaw pipe
1, Residual stress caused by uneven cooling. Residual stress is the internal self-balance stress in the absence of external force. The hot-rolled steel in all cross-sections has such residual stress. The larger the general section size, the more residual stress. Although the residual stress is self-balanced, the steel components under the action of external force or have a certain impact, such as deformation, stability, fatigue and other aspects may have an adverse effect;

2, After welding, the non-metallic inclusions in the lsaw pipe are pressed into flakes and stratification, which delaminates the performance of the straight-seam pipe in the thickness direction and may appear when the weld shrinks interlayer tear. The local strain induced by weld shrinkage often reaches several times the yield point strain, much greater than the load induced strain.