Preparation method for large-length welding spot-free copper-chromium-zirconium contact wire

Abstract

The invention relates to a preparation method for a large-length welding spot-free copper-chromium-zirconium contact wire. The copper-chromium-zirconium is prepared from 0.7 to 1.2 weight percent of Cr, 0.05 to 0.15 weight percent of Zr, and the balance of Cu and unavoidable impurities. The preparation method is characterized by comprising the following process flows of (1) casting, namely, preparing a copper-chromium-zirconium wire blank by an upcast continuous casting method, wherein the diameter of the wire blank is 25 to 35 mm; (2) performing cold machining, namely, performing cold machining with the deformation amount of 35 to 70 percent on the copper-chromium-zirconium wire blank; and (3) performing annealing treatment, namely, performing annealing treatment on the wire blank subjected to the cold machining, wherein the temperature is controlled to be 600 to 800 DEG C and the heat preservation time is 1 to 5 hours, and cooling the wire blank along with a furnace. According to thepreparation method for the large-length welding spot-free copper-chromium-zirconium contact wire, uniformity of a contact wire structure and fineness of crystal particles are ensured by setting a process flow and setting each process flow parameter, so that the large-length welding spot-free copper-chromium-zirconium contact wire can be prepared.

Description

technical field [0001] The invention relates to a method for preparing copper alloy wires, in particular to a method for preparing large-length copper-chromium-zirconium contact wires without solder joints. Background technique [0002] At present, alloys such as copper-magnesium and copper-tin are commonly used in contact wires for electrified railways. As the speed of high-speed rail continues to increase, higher requirements are placed on the electrical conductivity, strength, and high-temperature softening resistance of contact wire materials. As an alloy with high electrical conductivity, high strength and high temperature softening resistance, copper chromium zirconium can meet the requirements of high-speed railway contact lines above 350Km / h. Copper-chromium-zirconium wires (rods) currently on the market are produced using the "vacuum casting + hot extrusion" process, which is limited by the small ingots prepared by vacuum casting (generally below 300Kg), so it is im...

AI Technical Summary

Problems solved by technology

Copper-chromium-zirconium wires (rods) currently on the market are produced using the "vacuum casting + hot extrusion" process, which is limited by the small ingots prepared by vacuum casting (generally below 300Kg), so it is impossible to produce large lengths without welding Copper Chromium Zirconium Alloy Wire for Points

[0003] The invention patent application number is CN201310216235.X published "A High-strength and High Conductivity Copper-Chromium-Zirconium Alloy Long Wire Preparation Process". wire, this method requires ingot heating, high energy consumption, cumbersome process, and is not suitable for industrial mass production

[0004] The patent application number for invention is CN201510365622.9, which published "A Production Process for Thermomechanical Treatment of Large-length Cu-Cr-Zr-Si Alloy Contact Wire", which adopts horizontal continuous casting, hot rolling or continuous extrusion, solid solution, Cross-sectional area of ​​110-150mm prepared by cold rolling, aging and drawing of finished products 2 Copper-chromium-zirconium contact wire process, in which the continuous casting rods with a diameter greater than 80mm are processed by hot rolling, and heat treatment above 900°C must be carried out before and after hot rolling. Although the recrystallized and uniform structure of the finished product is guaranteed, there is energy consumption Higher, low yield; the continuous extrusion process is used for continuous casting rods with a diameter of less than 30mm. There are still differences in product organization, which will affect the performance of products such as repeated bending and torsion

[0005] Invention patent CN201710906689.8 published "A Copper-Chromium-Zirconium Alloy Contact Wire and Its Production Process". The process adopts upward continuous casting, continuous extrusion, first cold working, solution treatment, second cold working, and aging treatment The process of preparing copper-chromium-zirconium contact wire with drawn products is similar to the process of continuous extrusion processing in the above-mentioned CN201510365622.9, and the structure cannot be uniform

Therefore, there are the following problems when processing according to the methods in the invention patents CN201510365622.9, CN201710906689.8 and CN201310216235.X: one is that the extrusion tooling die wears seriously and the service life is low; the other is that the extrusion billet has inclusions, Surface roughness and other defects affect the final quality of the product

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