Electrical copper row is a high-current conductive copper, used for high and low voltage electrical appliances, switch contacts, power distribution equipment, bus ducts and other electrical equipment, but also widely used in metal smelting, electrochemical electroplating, chemical caustic soda and other ultra-high-current smelting or electrolysis equipment; section shape for the 4 rounded corners have technical requirements of the rectangular section; with mechanical properties and conductive properties.
Copper row production process
Copper row production process is mainly divided into the traditional rolling and extrusion of two kinds of technology, process flow is long, complex processes, energy consumption, low material utilization.
A. Large ingot hot rolled coil billet – high precision cold rolling method: large ingot hot rolled coil billet, the process is mature, hot rolling can be sufficient to change the casting organization, but the process is long, equipment investment.
B. Horizontal continuous casting billet – high precision cold rolling method: horizontal or on the lead continuous casting billet, process flow is short, less investment in equipment, cold rolled residual casting organization, the need for milling resulting in a low rate of material.
Continuous extrusion process: the new continuous extrusion process technology, can combine the advantages of the above two processes, the product grain organization (comparable to the organization of hot rolling), short process, high rate of finished product, less investment in equipment and plant, reduce the threshold of entry into the industry.
Continuous extrusion process advantages:
►The use of continuous casting and rolling of the coil as raw materials, supply convenience, no extrusion of the residual pressure, high material utilization rate, generally up to 95%, good uniformity of organization and properties.
►Continuous extrusion utilizes the heat generated by friction to raise the temperature without heating, thus saving energy.
►Less process, high production efficiency, high product yield.
►Can realize continuous production of products without interval time.
►Can produce ultra-long products
Traditional processing methods generally do not exceed 30-50m, while the length of using continuous extrusion method can generally be between thousands of meters until tens of thousands of meters, delivered in rolls, easy to transport.
Typical applications of continuous extrusion:
► Manufacture of tubes for refrigeration
► Cable TV coaxial cable outer conductor, communication signal cable sheath manufacturing
► Aluminum clad steel wire manufacturing
► High-speed railroad copper alloy contact wire manufacturing
► Copper flat wire, copper row manufacturing
► Oxygen-free copper rods Extra wide rows of continuous extrusion production: continuous extrusion width is limited, the main reason for the width range of up to 300mm, the
Key technical problems: how to fill the cavity, how to ensure the uniformity of the flow rate in the strip extrusion process.
Solution.
►Explore from the billet preheating temperature, the setting of mold parameters and the reasonable selection of extruder power.
►Cavity design
►Die material and cooling Organization properties after extrusion:
►The organization of the material after continuous extrusion is recrystallized organization, without the streamline organization of plastic forming;.
►The organization is uniform, fine, the surface is smooth and flat without oxidation, no need for surface treatment, can be directly for subsequent rolling processing;.
►Copper extrusion hardness of about HV60-70, belongs to the soft state; suitable for subsequent large deformation calendering processing.
Suggested process flow for producing ultra-thin copper rows for bus ducts:
Upper lead → extrusion → rolling → annealing → drawing
Billet rolling volume is limited, the thickness of rolled semi-finished products is generally greater than 2mm, the use of two-roll mill can be satisfied, to avoid functional waste.
Hollow cross-section conductive rows (profiles) continuous extrusion manufacturing: hollow cross-section copper rows (profiles) are widely used in electronics, electric power and other fields, multi-hollow anisotropic cross-section rows in the production of difficult and expensive, the market is difficult to see.
Traditional – hollow ingot billet perforated extrusion method: only the production of simple shapes, large size (diameter of 50mm or more); thin-walled, small aperture, the length of the profile production difficulties.
Traditional – stretching method: mainly produces anisotropic tubes with uniform wall thickness; it is difficult to realize and uneconomical for anisotropic tubes with uneven wall thickness.
International leading production technology: wide-row continuous extrusion-straight row extrusion, bending before straightening and hollow-row continuous extrusion.
