After hot-rolled seamless steel tubes, the grain refinement of steel, the ingot destroy the cast structure, eliminate defects and microstructure of the resulting dense PIPE, improved mechanical properties. Air bubbles present before the steel pipe, cracks and loose, after hot rolling at high temperature and pressure will be welded together.
 
Although there are many advantages of hot-rolled seamless steel pipe, but its shortcomings must be clear, after the hot-rolled steel, non-metallic inclusions in steel interior is pressed into thin slices, stratification. Layered in the thickness direction of the steel in tension performance deteriorated significantly, there interlayer tear weld shrinkage.
 
Been to hot-rolled steel, must have advanced technology, if technology does not pass, steel uneven residual stress caused by cooling during hot rolling. Residual stress in the absence of external forces are balanced inside, but in the case of steel external forces under are affected to some degree, for example, will have some impact in terms of deformation, stability, anti-fatigue.
 
When the steel after hot rolling, edge width and thickness control is not good in this regard due to thermal expansion and contraction principle, the beginning of hot rolled steel, length, thickness are standard, but in the end there will be some errors during the cooling, for edge width wider steel thickness thicker then a negative difference will be more obvious.