Hot rolled seamless steel pipe advantage and disadvantages
Jan 25, 2024
SMLS Hot Rolled Steel Pipe Supplier-GNEE
- Advantages
It can destroy the casting organization of the ingot, refine the grain of the steel, and eliminate the defects of the microstructure, thus making the steel organization dense and improving the mechanical properties. This improvement is mainly reflected in the direction along the rolling, so that the steel is no longer isotropic body to a certain extent; casting the formation of bubbles, cracks and loose, but also in the role of high temperature and pressure can be welded together.
- Disadvantages
1. After hot rolling, the non-metallic inclusions inside the steel (mainly sulfides and oxides, and silicates) are pressed into thin sheets, and delamination (interlayer) occurs. Delamination greatly deteriorates the tensile properties of the steel in the thickness direction, and there is a risk of interlayer tearing during weld shrinkage. Weld shrinkage induced local strain often reaches several times the yield point strain, much larger than the load-induced strain;
2. Residual stresses caused by uneven cooling. Residual stress is in the absence of external forces within the self-equilibrium stress, a variety of cross-sectional hot-rolled steel have such residual stress, generally the larger the cross-section size of the steel, the greater the residual stress. Although the residual stress is self-equilibrium, but the performance of steel components in the external force or have a certain impact. Such as deformation, stability, fatigue resistance and other aspects may have an adverse effect.
3. Hot rolled steel products, for the thickness and width of the edge of this area is not good control. We are familiar with the thermal expansion and contraction, due to the beginning of the hot rolled out even if the length and thickness are up to standard, and finally after cooling there will be a certain negative difference, this negative difference in the wider the width of the edge, the thicker the thicker the more obvious performance. So for the large steel, for the steel edge width, thickness, length, angle, and the edge of the line can not require too precise.
