Disadvantages of hot rolled seamless steel tubes
Hunan Great Steel Pipe shared the advantage of hot-rolling seamless steel pipe previously. Next, we will continue to share its disadvantages for all of you.
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.
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.
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