Domestic manufacturers of LSAW pipes usually improve their properties by adding alloys to the material. After cold drawing, stress annealing must be carried out to eliminate the residual stress of the material to prevent the fracture of LSAW pipes.
Currently, China's LSAW pipe manufacturers improve the strength of the metal by cold drawing deformation, but this is at the expense of the shape and toughness of the metal.
Cold-drawn straight seam welded pipe is based on the market with high dimensional accuracy and high strength performance, and it is necessary to ensure that the deformation is within a certain range in order to maximize the performance of the material and reduce the adverse effects on the material.
Straight seam welded pipe if the deformation is small, neither to meet the flatness of the parts and dimensional accuracy requirements, but also can not meet the strength requirements of the components, deformation is too large, then the plasticity and toughness of the straight seam welded pipe will be greatly reduced, the grain pulled too long and can not form a fiber structure, the metal has a significant anisotropy.
The axial direction of the cold-drawn straight seam welded pipe is parallel to the elongation direction of the grains, the strength of the cold-drawn straight seam welded pipe is perpendicular to the elongation direction of the grains, but the strength is reduced, and the maximum stress of the hydraulic cylinder exists in the radial direction of the straight seam welded pipe, so that the deformation is too large, and can not give full play to the performance of the cold-drawn pipe.
English