Changsha Xiangjia Metal Materical Co., Ltd.

There are differences in the implementation of hot rolling and cold rolling of   spiral pipes . Both processes are used to form steel sections or plates and have a significant impact on the structure and properties of the steel. Typically, the rolling of steel is dominated by hot rolling, while cold rolling is mainly used for the production of fine-type sections and thin plates. During hot rolling, the casting organisation of the ingot can be destroyed, grain refinement can take place and microstructural defects can be eliminated, resulting in a dense steel structure and improved mechanical properties. This improvement is mainly reflected in the direction along the rolling direction, making the steel to a certain extent non-isotropic; at the same time, under high temperature and pressure, the casting of bubbles, cracks and loose parts can be welded together. Cold rolling is at room temperature, through cold drawing, cold bending, cold drawing and other cold processing of steel plat...

The welding process of   submerged arc LSAW steel pipe   is to connect the welding wire and steel plate by filling the weld to achieve the welding of LSAW steel pipe, while high frequency LSAW steel pipe uses the skin effect of high frequency current to melt the edge of the weld of the steel plate quickly, so that the weld will be fused together under the pressure of the external force, and the welding will be achieved. In terms of moulding, double-sided submerged arc LSAW steel pipe adopts JCOE moulding, which is cold-formed by stamping the steel plate one by one through the press, while high-frequency LSAW steel pipe adopts the moulding process in which the FXH multi-rolls are gradually turned into round shapes. In addition, there are obvious differences between submerged arc LSA steel pipe and HF LSA steel pipe in terms of production range, materials used, industries used and appearance. The production range of submerged arc steel pipe is from 325mm to 1420mm in diameter, a...

In the cross-section of   straight seam steel pipes , there may be inconsistencies in the outer diameter, where the maximum and minimum outer diameters are not necessarily perpendicular. Ellipticity (or out-of-roundness) is defined as the difference between the maximum and minimum outer diameters. To control ellipticity, some steel pipe standards specify that ellipticity should not exceed 80% of the outer diameter tolerance. straight seam steel pipes exhibit curvature in the lengthwise direction, with the degree of curvature expressed in terms of bending. The standard specifications for bending generally fall into two categories: 1. **Local Bending**: Local bending is determined by measuring the chord height (in mm) at the point of maximum curvature using a one-meter long straight edge, with bending expressed in units of mm/m, for example, 2.5mm/m. This method is also applicable for determining bending at the pipe ends. 2. **Total Bending Along the Entire Length**: Total bending is...