We have mention the definition of hot rolling seamless steel pipe previously, today, Prime Steel Pipe will continue to talk about the advantages and disadvantages of hot rolling seamless steel tube with all of you.
Advantages of hot rolling seamless steel pipe
Can damage the ingot casting organization, refine the grain of steel, and eliminate the defects of microstructure, so that the steel structure is dense, mechanical properties improved. This improvement is mainly reflected in the rolling direction, so that the steel to a certain extent is no longer an isotropic body; pouring the formation of bubbles, cracks and loose, but also in the high temperature and pressure under the welding.
Disadvantages of hot rolling seamless steel pipe
1. After hot rolling, non-metallic inclusions (mainly sulfides and oxides, as well as silicates) inside the steel are pressed into flakes and delamination (interlayer). Stratification makes the performance of the steel in the thickness direction greatly deteriorated, and there may be tearing occurs when the weld shrinks. The local strain induced by the weld shrinkage often reaches several times the yield point strain, much larger than the load caused by the load;
2. Unstable cooling caused by residual stress. Residual stress is in the absence of external force under the action of internal self-balanced, all kinds of cross-section of hot-rolled steel have such residual stress, the general steel cross-sectional size, the greater the residual stress. Although the residual stress is self-balanced, but the steel components under the action of external force or have a certain impact. Such as deformation, stability, anti-fatigue and other aspects may have a negative effect.
3. Hot-rolled steel products, for the thickness and side width of this bad control. We are familiar with the thermal expansion and contraction, because the beginning of the hot rolled out even if the length of the thickness of the standard, the final cooling or there will be a certain negative difference, the wider the width of the gap, the thicker the more obvious the performance. So for large steel, for the steel side width, thickness, length, angle, and the edge can not be too precise requirements.