Mechanical principle and production process of cold drawn tube

- Jan 09, 2019-

The mechanical principle of the cold drawn tube is that when the cold drawing is carried out, the steel tube is plastically deformed by a certain shape and size of the mold under the action of force. At present, the extraction method in production can be roughly divided into three types: reduced diameter extubation, reduced outer wall extubation and reduced inner wall extubation. When cold drawn, the steel tube occurs under the action of drawing force, positive pressure and friction. Corresponding deformations are mostly subjected to three stages of diameter reduction, wall reduction and sizing, and corresponding stresses are generated inside the deformation zone, wherein the axial direction is tensile stress, the radial direction and the circumferential direction are compressive stress, and the metal is always in the process of extubation. Pulling and two-direction compressive stress state, which is the basic mechanical feature of the cold drawn tube deformation process.


The cold drawn tube is also a kind of steel pipe, which is different from the hot rolling (expansion) pipe according to the different classification of the production process. It is formed by multi-pass cold drawing in the process of expanding the diameter of the capillary tube or the raw material tube, and is usually carried out on a single-chain or double-chain cold drawing machine of 0.5 to 100T. Cold rolling (dial) steel pipe in addition to general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking pipe, mechanical processing pipe, thick wall pipe, small diameter plus inner mold cold drawn pipe other steel pipe It also includes carbon thin-walled steel pipes, alloy thin-walled steel pipes, stainless thin-walled steel pipes, and special-shaped steel pipes.

The outer diameter of the cold drawn tube can be up to 6mm, the wall thickness can be up to 0.25mm, the outer diameter of the thin-walled tube can be up to 5mm, the wall thickness is less than 0.25mm, the precision and surface quality are obviously better than the hot-rolled (expanded) tube, but by the process Restricted, its caliber and length are subject to certain