Production of copper or copper-alloy pipes

Abstract

A method for manufacturing copper (or Cu-alloy) tube includes such steps as removing surficial oxide layer from raw tube, high-speed rolling by a 4-roller rolling mill, fast cooling by a two-pass cooler, and straight cold drawing.

Description

technical field [0001] The invention relates to a processing method for copper or copper alloy pipes, in particular to a processing and manufacturing method for manufacturing high-precision copper or alloy pipes. Background technique [0002] At present, the production technology of copper and copper alloy pipes at home and abroad mostly adopts the extrusion piercing and rolling method, the horizontal continuous casting three-roll planetary mill (PSW, planetenschragwalzwerk (German)) skew rolling method and the preheated billet three-roll planetary mill (PSW ) skew rolling method. As shown in Fig. 1 and Fig. 2, the three-roll planetary rolling mill (PSW) includes a box body 94, a rotor 93 arranged in the box body 94, and a roll 91, and the roll 91 revolves in the direction of the arrow M, and in the direction of the arrow N Make a rotation. The rolling principle of the above-mentioned three-roll planetary rolling mill is that three rolls 91 are distributed around the workp...

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Problems solved by technology

[0003] China Patent Application No. 02138022.8 discloses a method for manufacturing copper and copper alloy pipes by warm processing. The former steps include preheating the billet, rolling the billet and cooling the rolled piece. The main feature is that the billet is preheated before rolling. Between the ambient temperature and the recrystallization temperature, and then rolled through a three-roll (PSW) rolling mill to overcome the uneven rolling deformation, but in actual operation, preheating the tube billet cannot achieve its real purpose Therefore, due to the heat generated by the deformation process of the billet during the rolling process, the temperature of the billet can actually reach the temperature required for the recrystallization of the billet, so increasing the preheating process cannot play a role in recrystallization of the billet Any effect, on the contrary, it will increase the manufacturing cost of the tube blank due to the increase of the preheating process, increase the preheating equipment, consider the appropriate preheating method, and waste energy; the temperature generated by preheating the tube blank is not easy to control, and preheating After heating, the heat will be lost during the deformation process, resulting in a decrease in temperature. Therefore, the temperature generated by preheating cannot be superimposed with the temperature caused by the heat generated by the deformation of the tube blank during processing; in addition, because the metal tube blank is a benign material for heat conduction, In the preheating process, the temperature of the head of the tube blank is much higher than the temperature of other parts, which is a technology that is difficult to achieve in actual operation, and the tube blank has already undergone the step of removing scale before preheating. During the preheating process, due to the temperature rise High, in order to prevent the surface of the tube blank from being oxidized again at high temperature, it is necessary to apply a certain protective gas to protect the tube blank during the preheating period, so it is necessary to increase equipment, raw materials and processes to further reduce the production of the tube blank Efficiency, increase the cost of tube blank manufacturing

[0004] China Patent Application No. 03149757.8 discloses another method for manufacturing copper and copper alloy tubes with a planetary rolling mill. The three-roller (PSW) rolling mill is used to roll the tube billets, so that the tube billets are rolled at a temperature of 701-850 ° C, and the reduction in area is reduced. 85-95%, the rolling speed is 12-30m / min, but the above method has the disadvantages of large distortion and deformation of the rolled piece, low rolling speed, small diameter of the rolled tube, etc.

[0005] Please refer to Figure 2, the three rolls 91 and the workpiece 92 form an approximately triangular cross-section during the rolling process. It is precisely because of this irregular cross-section formed in a special space that the workpiece twists and deforms greatly when it is rotated. It is easy to form quality defects of rolled tubes, and the rolling resistance is relatively large. The wall thickness of the bite line 911 and the breakaway line 912 is quite different, and the uniformity is poor. Even after rounding, the difference in wall thickness (T) Still relatively large, Tmax-Tmin≥0.35mm, which will adversely affect the production of subsequent processes, resulting in low precision

[0006] Therefore, the traditional extrusion piercing and rolling method has many processes, including a heating process in the middle, the manufacturing cost is high, and the yield is low, the product precision is poor, and it is difficult to produce super long pipes

Horizontal continuous casting three-roll planetary mill (PSW) cross-rolling method and preheated slab three-roll planetary mill (PSW) cross-rolling method also have low rolling speed and small rolled pipe specifications, which cannot produce large-diameter copper pipes and waste disadvantages such as energy

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