Manufacturing method for high-precision cold-drawing welded pipe

Abstract

The invention relates to a manufacturing method for high-precision cold-drawing welded pipe. The manufacturing method for the high-precision cold-drawing welded pipe includes steps of longitudinal shearing, roll-bending forming, high-frequency welding, weld joint treatment, sizing, online eddy current inspection, pre-straightening treatment, pipe cutting, stress relief annealing, pinching, acid dipping, phosphating, saponification treatment, cold drawing, induction furnace quenching treatment, tempering treatment in a box type furnace, straightening treatment, honing, magnetic leakage detection and pipe cutting measurement. The product obtained through the manufacturing method for the high-precision cold-drawing welded pipe is high in yield strength, high in tensile strength, precise in size, smooth in surface, fast in processing forming speed and high in yield, the manufacturing precision is obviously improved, the cold-drawn welded pipe is good in surface smoothness and low in roughness, the subsequent gold processing amount is reduced, the steel material use ratio is improved, the manufacturing cost is lowered, and the energy conservation and environment protection are boosted.

Description

technical field [0001] The invention belongs to the technical field of steel pipe preparation, and in particular relates to a method for manufacturing a high-precision cold-drawn welded pipe. Background technique [0002] In the prior art, the production process of the cylinder body of the hydraulic oil cylinder is generally made of hot-rolled seamless steel pipe, which is produced by a combined cutting process of boring and rolling. Since one of the biggest defects of the seamless steel pipe is uneven wall thickness, The main reasons are uneven heating of the tube billet, instability of the centering roll caused by the uncorrected rolling line of the piercer, wear of the plug, eccentricity of the rear hole of the plug, incorrect centering hole of the tube billet, excessive curvature of the tube billet, etc. The reason is that it is technically difficult to remove all the above reasons one by one. Therefore, the yield of seamless steel pipes is relatively low; Concave and o...

AI Technical Summary

Problems solved by technology

Using this method to manufacture the cylinder body of the hydraulic cylinder, the production speed is slow, the energy waste is large, the metal utilization rate is low, and the yield is also low.

[0003] In the prior art, the welded pipe production process is a relatively mature production technology. However, welded pipes generally cannot be used as cylinder blocks for hydraulic cylinders. The following problems limit their application in the manufacture of hydraulic cylinders: 1), welded pipes The accuracy of the pipe itself is relatively low, and its roundness is difficult to be reliably guaranteed; 2) When the welded pipe is welded, the surface weld is easy to handle

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