The main difference of the hot-rolled pipe and cold-rolled s

The main difference of the hot-rolled steel and cold-rolled steel pipe:

1, cold-rolled steel pipe formed steel allows section presents partial flexion, allowing plenty of carrying capacity after the application bar buckling; hot-rolled steel steel does not allow cross-section seizure partial flexion.

The reason of the residual stress of the hot-rolled steel pipe steel and cold-rolled steel section steel cross section distribution can vary considerably. The residual stress on the cold-formed steel cross section distribute bending type, hot rolling steel or welded steel residual stress distribution in the cross-section is a film type.

3 comfortable changing the stiffness of the hot-rolled steel steel, hot-rolled steel-beam torsional properties superior to cold rolled steel steel, cold rolled steel steel.

A cold-rolled steel pipe

At room temperature, cold working, after cold-drawn, cold-formed, cold drawn steel sheets or strips processed into various types of steel.

Advantages: fast forming speed, high yield, does not damage the coating can be made of a variety of cross-section to conform to the use of the conditions of demand; cold rolled steel to the steel to produce a lot of plastic deformation, which advances in the steel The succumb point.

Defects: 1. Course, the molding process without hot plastic austerity, but still exists within the residual stress in the cross-section, will inevitably have an impact on steel as a whole and partial buckling characteristics; cold rolled steel steel style ordinary ashamed cross section, making the cross-section comfortable changing the stiffness is lower. Likely to show a change in the flexural compression likely to show the bending and torsion buckling, torsional performance is poor; cold rolled steel formed steel wall thickness is smaller, and no thickening at the corner of plate convergence accept partial concentrated load can be weak.

Two hot-rolled steel pipes

Advantages: the ability to destroy the cast structure of the steel ingot, and the refinement of crystal grains of the steel, and eliminate the defects of the microstructure, so that the compacting steel tissue, improve the mechanical properties. This improvement is mainly in the direction of the rolling control, at a certain level so that the steel is no longer isotropic; bubbles, cracks and loose pouring constituted, under the high temperature and pressure can also be welded together.

Flaws: 1. After the hot-rolled steel, steel inside the non-metallic inclusions (mainly sulfides and oxides, as well as silicates) was pressed into sheet, showing delamination. The layering of the steel in the thickness direction by the pull performance deteriorated significantly, and may tear when weld shrinkage rendering interlayer. The part of the strain induced by weld shrinkage often reach succumb to a multiple of the strain, the strain is much greater than the load caused; 2. Average cooling the formation of residual stress. The residual stress is the autocorrelation balanced in the absence of external force, the internal stress, the hot-rolled steel steel of various cross-section has such residual stress the greater the,steel piping ordinary steel cross-sectional size, the larger the residual stress also. While residual stress is self-balanced, but still has some influence in the performance of the steel members under external force. Such as deformation, stability, anti-fatigue, etc. are likely to produce the adverse effect.