High-precision cold drawn seamless carbon steel pipe abroad is generally increased in the metal alloy approach to improve material performance in the cold drawn seamless steel pipe, after all need to stress annealing, to eliminate residual stress of materials, to improve the organization of materials,improve the plastic material, thus preventing the purpose of seamless steel pipe fracture failure occurs.

At present, the common cold drawn seamless steel tube material are 45 # or 20 # steel 27SiMn steel, deformed by cold drawing of metal strength increases; However, it is at the expense of metal plasticity, toughness is the price.High-precision cold drawn seamless steel pipe is its high dimensional accuracy and high strength properties and market-based, it must ensure that the deformation within a certain range, in order to maximize the performance of materials to reduce materialadversely affected.Cold drawn seamless steel tube deformation is too small to achieve the surface finish and dimensional accuracy requirements, they can not achieve the strength index components; deformation is too large, seamless steel tubes of plastic, to reduce excessive toughness, and grain is pulled excessivelyslender, forming a fibrous tissue, the metal will have obvious anisotropy.Cold drawn seamless mild steel pipe axial, elongated parallel to the grain direction, intensity increased; cold drawn seamless steel radial, elongated perpendicular to the grain direction, but lower strength, while the biggest hydraulic cylinderStress is present in the radial seamless, so, too much distortion on the performance of fully cold drawn pipe negative.

For steel and fibrous tissue appear dislocations, vacancies and other crystal defects, generally taken to annealing or normalizing heat treatment methods to eliminate them.The purpose of annealing is grain refinement, elimination of tissue defects, reduce the hardness and improve ductility, but also easy to cold.Cold drawn seamless steel pipe production, indispensable annealing equipment, so, to develop an appropriate annealing process is to ensure that cold-drawn seamless structural steel pipe qualified organization, product defect does not appear necessary condition for fracture.If the manufacturer to unilaterally reduce production costs, reducing annealing process, is bound to adversely affect product quality.