Anhui Litong Rare Earth Steel Cable Co., Ltd.: Aluminum-Clad Steel-Cored Aluminum Stranded Wire, Empowering Efficient and Green Power Transmission
Driven by the dual forces of new energy transformation and power grid upgrading, the power transmission sector imposes increasingly stringent requirements on conductor products—they must not only deliver excellent electrical conductivity but also balance mechanical strength, weather resistance, and energy efficiency. As a benchmark enterprise in China's rare earth steel cable industry, Anhui Litong Rare Earth Steel Cable Co., Ltd. has deepened its R&D in power transmission materials. Its flagship product, the aluminum-clad steel-cored aluminum stranded wire, has emerged as the preferred solution for medium and high-voltage power transmission projects, thanks to its core advantages of "strong core, tough structure, and high efficiency," injecting robust momentum into the construction of green power grids.
The core innovation of the aluminum-clad steel-cored aluminum stranded wire lies in its structural design: it features an aluminum-clad steel wire as the reinforcing core, with high-conductivity hard aluminum wires stranded on the outer layer, forming a synergistic system of "steel core bearing load and aluminum layer conducting electricity." This structure inherits the high tensile strength and fatigue resistance of the steel core while leveraging the excellent electrical conductivity of aluminum, perfectly addressing the industry pain point of traditional conductors—"the trade-off between strength and conductivity." It is also one of the core power products developed by the company based on rare earth alloy modification technology.
I. Core Manufacturing Processes: Meticulous Craftsmanship for Quality Excellence
(1) Raw Material Selection: Controlling Basic Performance from the Source
The quality of raw materials directly determines the final performance of the conductor. Anhui Litong Rare Earth Steel Cable Co., Ltd. has established strict raw material procurement standards: the steel core adopts high-quality low-alloy steel wire rods produced by Shagang Group, with a tensile strength of ≥1270MPa and an elongation rate of ≥7%, ensuring the mechanical bearing capacity of the reinforcing core; the aluminum rods are made from high-conductivity aluminum ingots with a purity of ≥99.7%, processed through continuous casting and rolling, achieving an electrical conductivity of over 61% IACS, laying a foundation for efficient power transmission. Each batch of raw materials undergoes 8 rigorous inspections before storage, including composition analysis, mechanical property testing, and conductivity measurement, with unqualified materials firmly rejected.
(2) Metallurgical Cladding: Innovative Technology for Strong Interlayer Bonding
The effective combination of aluminum and steel is crucial to product performance. The company adopts the industry-leading continuous extrusion cladding process: aluminum ingots heated to 450℃ are tightly clad on the surface of derusted and preheated steel cores through extrusion dies, achieving metallurgical bonding between aluminum and steel. This bonding method eliminates issues such as interlayer separation and oxide peeling that may occur in traditional cladding processes, forming a solid integrated structure of aluminum layer and steel core. It not only enhances the structural stability of the conductor but also improves weather resistance, ensuring consistent performance under long-term tension and bending conditions.
(3) Precision Processing: Millimeter-Level Control for Product Accuracy
The clad composite wire billet undergoes multiple precision drawing processes, with diameter gradually reduced through dies, controlling the outer diameter tolerance of the conductor within ±0.05mm. In the stranding process, computer-controlled multi-head stranding equipment is used to strictly control the lay ratio of aluminum wires (maintained at 12-16 times the conductor diameter), ensuring uniform arrangement and balanced stress of outer aluminum wires, and avoiding local electric field concentration or mechanical strength degradation caused by uneven stranding. Before delivery, finished products undergo multiple tests, including DC resistance, tensile strength, torsion performance, and corrosion resistance, ensuring full compliance with GB/T 1179-2017 Round Wire Concentric Stranded Overhead Conductors standards.
II. Outstanding Performance Advantages: Multi-Dimensional Upgrades for Efficient Power Transmission
(1) High Efficiency and Energy Saving: Reducing Losses, Enhancing Transmission Efficiency
Compared with traditional steel-cored aluminum stranded wires, the aluminum-clad steel-cored aluminum stranded wire offers significantly improved conductivity. The metallurgical bonding between the aluminum layer and steel core reduces contact resistance, and the high-purity aluminum rods provide superior electrical conductivity, increasing the product's current-carrying capacity by 2-3% compared to ordinary steel-cored aluminum stranded wires. Taking a 110kV power transmission line as an example, the application of this product reduces power loss per kilometer by 4-6%, enabling energy savings of approximately 120,000 kWh per year for a 100-kilometer line. Its long-term energy-saving benefits are remarkable, aligning with the development needs of energy conservation and consumption reduction in power grids under the "dual carbon" goal.
(2) Lightweight and Stable: Reducing Burden, Ensuring Line Safety
The aluminum-clad steel-cored aluminum stranded wire is 5% lighter than traditional steel-cored aluminum stranded wires. This advantage directly reduces the load-bearing pressure on transmission line towers, not only reducing the consumption of tower materials and engineering construction costs but also enhancing the line's span capacity. Meanwhile, the product has a lower thermal expansion coefficient, reducing line sag by 1-2% during operation, effectively avoiding safety hazards caused by excessive conductor sag in high temperatures. It is particularly suitable for long-span transmission scenarios such as mountain valleys, cross-river, and cross-sea projects.
III. Main Application Scenarios: Comprehensive Coverage to Support Power Grid Upgrading
(1) Coastal Area Transmission Lines
China's coastal areas have high salt spray concentration and humidity, imposing extremely high requirements on the corrosion resistance of conductors. With its excellent anti-corrosion capability, the aluminum-clad steel-cored aluminum stranded wire of Anhui Litong Rare Earth Steel Cable Co., Ltd. has been successfully applied in projects such as the Zhejiang Zhoushan Islands Cross-Sea Power Transmission Project and the Fujian Xiamen Coastal Power Grid Upgrading Project, with a total supply exceeding 5,000 kilometers, effectively ensuring the stability and reliability of power transmission in coastal areas.
(2) Industrial Polluted Regions
In industrial polluted areas such as chemical parks and metallurgical plants, acid-base gases in the air are prone to corroding conductors. The product has been widely used in transmission line renovation projects in Jiangsu Suzhou Industrial Park and Shandong Zibo Chemical Base. Its ability to withstand acid-base erosion reduces line failure rates, ensuring continuous power supply for industrial production.
As an enterprise deeply engaged in the power transmission materials sector, Anhui Litong Rare Earth Steel Cable Co., Ltd. has always taken technological innovation as the core and quality control as the guarantee. In the future, the company will continue to optimize the production process of aluminum-clad steel-cored aluminum stranded wires, explore the application of rare earth alloys in conductors, further improve product conductivity and weather resistance, and provide higher-quality products and services for China's power grid upgrading and green energy development.