A method for compounding seamless pipes by using multi-layer metal ultra-thin coils

Abstract

A method of compositely preparing seamless pipes using multi-layer metal ultra-thin strip coils, including the following steps: (1) Calculate and cut the ultra-thin strip based on the diameter of the thick section of the core rod, the thickness of the ultra-thin strip and the pre-winding outer diameter; ( 2) Wrap the ultra-thin tape around the core rod, fix it and compact it; (3) Pass the ultra-thin tape roll wrapped with the core rod through the hole pattern of the forming roller group, and use the drawing force application device to pull the core rod. Drawing, the extremely thin strip coil is rolled and deformed between the thick section of the core rod and the forming roller set; (4) annealing treatment; (5) cold drawing, wall reduction and sizing. The method of the present invention can make an extremely thin metal strip roll into a seamless tube blank through one-time cold forming, simplifying the process and reducing costs; the finished product can be manufactured into more specifications, and has good application prospects.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a method for compounding seamless pipes by utilizing multi-layer metal ultra-thin coils. Background technique [0002] Metal seamless pipe is a long pipe with a hollow section and no seams around it. Because of its hollow section, it has the same torsional strength and lighter weight compared with solid round steel of equal diameter. , is widely used in fluid transport pipes, oil drill pipes, automobile drive shafts, bicycle frames and steel scaffolding, etc. With the development of micro-forming and micro-manufacturing, the preparation of small-diameter seamless pipes has gradually become one of the research hotspots ; Taking the medical field as an example, under the background of the rapid development of minimally invasive interventional medical engineering, minimally invasive devices and micromaterials are also gradually flourishing; according to the treatment o...

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Problems solved by technology

[0003] Compared with other types of processed products such as plates, rods, strips, forgings, etc., seamless metal pipes are products with long processes, complicated processing technology and high processing difficulty; existing seamless pipe preparation methods include forging, cross rolling Perforation, equal-diameter angle extrusion, diameter-angle pipe extrusion and hot extrusion combined; Pressing is applied to the blank to produce plastic deformation, so as to obtain the required shape and size of the forming processing method; the basic process mainly includes thickening, elongating and punching, and there are disadvantages such as long processing process and waste of metal; Cross-rolling piercing includes two-roll cross-rolling piercing and three-roll cross-rolling piercing, etc. The two-roll cross-rolling piercing method uses the tensile stress of the billet in the longitudinal direction to cause micro-cracks in the metal in the axial center of the round billet, and then expand into loose areas. , the resistance of the plug during piercing causes the difference in the speed of the inner and outer surfaces to produce shear strain. When the axial metal is loose, the plug participates in plastic processing, and the processing method of piercing the solid billet into a capillary tube; there are problems such as cracking in the center of the cavity when the two-roll cross-rolling piercing is pierced. Three-roll cross-rolling piercing To eliminate this problem, the central part of the tube blank before the plug only bears compressive stress; however, three-roll cross-rolling still has a complex control of piercing process parameters, which often leads to large metal flow resistance, rolling jams or Serious eccentricity of the threaded capillary, poor quality of the inner and outer surfaces of the tube, serious wear of the plug, etc.

Equal-diameter angular extrusion or the combination of radial-angle pipe extrusion and hot extrusion is an effective method for preparing ultra-fine crystallized pipes, but there are disadvantages such as excessive friction during processing, difficult control of process parameters, and high energy consumption.

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