Warm machining method for making copper or cu alloy pipe

Abstract

A warm machining technology for making Cu or Cu-alloy pipe includes such steps as machining surface of pipe blank, preheating to a temp between ambient temp and recrystallizing temp, high-speed rolling at temp higher than recrystallizing temp and fast cooling. Its advantages are simple process, high utilization rate of material, low cost and high quality.

Description

technical field [0001] The invention belongs to the metal pipe rolling technology. Specifically speaking, it uses the principle of warm processing and deformation heat treatment. The horizontal continuous casting of copper and copper alloy tube blanks is processed by surface machining, purification and preheating, and the high elongation coefficient and high In deformation rate rolling, after dynamic recrystallization occurs, rapid online cooling is performed to process and manufacture copper and copper alloy pipes. Background technique [0002] Existing manufacturing methods of copper and copper alloy pipes mainly contain three kinds such as piercing and rolling method, extrusion method and cold working casting and rolling method. However, the traditional first two methods have disadvantages such as many processes, low yield and high pipe manufacturing cost, and are gradually being replaced by other technologies. And the 3rd kind of cold working cast-rolling method, as th...

AI Technical Summary

Problems solved by technology

This incomplete recrystallization results in local instability in both tensile strength and elongation of the finished pipe

And because of this cold rolling method, the dynamic recrystallization process does not start until the middle of the deformation zone, so that the recrystallization is incomplete and insufficient, which is not conducive to the fineness of the cross-sectional structure of the pipe and the elimination of pores and inclusions

And the tube blank is sent into the deformation zone at ambient temperature, which will cause serious impact on the bearings and gears of the rolling mill and affect their service life, and will also cause unstable rolling quality in winter and summer

In particular, this cold rolling method does not perform any purification treatment on the casting defects that inevitably exist on the surface of the billet, which will inevitably remove the slag inclusions and Casting defects such as air holes are mixed in the cross-sectional structure of the pipe

Looking at the existing methods of cold-working cast-rolled copper and copper alloy pipes, the folded cracks in the finished pipes, incomplete recrystallization, and the existence of casting defects on the surface of the billet seriously affect the quality of the finished pipes and the follow-up process. The lack of quality of deep-processed finished products is obvious