The cold drawn seamless pipe must be certain defects and quality issues in the production process, which need strict attention.it exists steel fibrous tissue as well as dislocations, vacancies, and other crystal defects, generally taken to the annealing or normalizing heat treatment means to eliminate them. The purpose of annealing is grain refinement, organizations eliminate defects, reduce hardness, plasticity, and also facilitate the cold. Cold drawn seamless steel pipe production, annealing equipment indispensable to develop an appropriate annealing process is to ensure that cold drawn seamless steel pipe qualified organization, the product is not a necessary condition for fracture defects. If the manufacturer to the one-sided to reduce production costs, to reduce the annealing process is bound to adversely affect the quality of products.
Cold drawn seamless pipe deformation is too small, can not reach the surface finish and dimensional accuracy requirements, they can not achieve the strength index of the component; deformation is too large, seamless pipe of plastic, the toughness decreases too much, and too much grain is pulled slender, the formation of fibrous tissue, the metal will have a significant anisotropy. Cold drawn seamless steel pipe axial, parallel to the elongated direction of the grain, the strength increases; cold drawn seamless steel pipes of the radial and perpendicular to the elongated direction of the grain, but decreased strength, and the hydraulic cylinder the stress is radial in the seamless steel pipe, so the deformation is too large to give full play to the performance of the cold drawn pipe.
Cold drawn steel pipe is used for mechanical structure, hydraulic equipment, high dimensional accuracy, and surface finish, good precision cold drawn seamless pipe. Using precision seamless pipe manufacture machinery structure or hydraulic equipment, etc., can greatly reduce the mechanical processing time, improve material utilization, and help to improve the product quality.
If got smaller size and better quality seamless pipes must take cold-rolled, cold drawn, or both methods. Cold rolled usually in the two-roll mill, steel rolling in the ring pass a variable cross-section hole slot and fixed cone head. Cold drawing is usually in the 0.5 ~ 100T single chain or double chain drawing machine.