Hot rolled SA210C seamless steel pipe can destroy the casting structure of ingot, refine the grain of steel, eliminate the structure defects, make the steel structure compact and improve the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the hot rolled SA210C seamless steel pipe no longer has certain isotropy. The bubbles, cracks and looseness produced in the casting process of hot rolled SA210C seamless steel pipe can also be welded under high temperature and high pressure.
Disadvantages of hot rolled SA210C seamless steel pipe: after hot rolling, the non-metallic inclusions (mainly sulfide and oxide, and silicate) in hot rolled SA210C seamless steel pipe are pressed into thin sheet, and delamination (interlayer) occurs. Delamination seriously affects the tensile properties of hot rolled SA210C seamless steel pipe in the thickness direction, which may lead to interlaminar tearing when the weld shrinks. The local strain of hot rolled SA210C seamless steel pipe caused by weld shrinkage is often several times of the yield point strain, which is much larger than the local strain caused by load.
