Application of Copper Roll Shell in Twin-Roll Casting and Rolling Process
Release time:
Nov 11,2025
Introduction
Twin-roll casting and rolling technology is a near-net shape forming process that integrates solidification and hot rolling, and is widely used in the production of aluminum strip blanks. The traditional casting and rolling process is limited by the thermal conductivity of the roll shell material, resulting in low casting and rolling speed and big strip thickness, which makes it difficult to meet the needs of high-efficiency production. Copper roll shells, with excellent thermal conductivity (3–4 times that of steel roll shells), have become a key technological breakthrough for realizing ultra-thin and rapid casting and rolling. Based on a number of research literatures, this paper systematically sorts out the material properties, performance advantages, application challenges and solutions of copper roll shells, and provides promotional guidance to promote their industrial application.
I. Material Properties and Optimization of Copper Roll Shell
1. Material Composition and Performance Advantages
- Base material: Most copper roll shells are made of beryllium bronze (Be-Cu alloy), such as QBe2 and Be20C. The thermal conductivity of these alloys ranges from 100 to 250 W/(m·K), which is much higher than that of steel roll shells (approximately 30 to 45 W/(m·K)).
- Mechanical properties: Through composition optimization (e.g., adjusting the contents of beryllium, nickel, and titanium), beryllium bronze maintains high strength (tensile strength ≥ 1000 MPa) while its elongation is increased to 2–10% and its softening temperature is raised to above 200°C.
- Heat treatment process: Solution treatment (780–800°C) and aging treatment (310–330°C) can significantly improve the material's hardness and fatigue resistance, enabling the roll shell to adapt to the thermal shock environment of high-speed casting and rolling.
2. Comparison with Traditional Steel Roll Shell
Property | Steel roll shell | Copper roll shell | Advantage description |
Thermal conductivity | 30–45 W/(m·K) | 100–250 W/(m·K) | Heat dissipation efficiency is increased by 3–4 times, accelerating solidification. |
Limit casting-rolling speed | 4–6 m/min | 10–12 m/min | Speed is increased by 2.5 times, leading to a significant improvement in production capacity. |
Peak thermal stress | High (prone to cracking) | Reduced by 30–50% | Thermal damage resistance is enhanced, extending service life. |
Strip quality | Easy to cause segregation | More uniform structure, refined grains | Improves deep drawing performance and surface quality. |
II. Analysis of Performance Advantages of Copper Roll Shell
1. Improvement of Thermal Conductivity and Casting-Rolling Speed
- Thermal resistance model analysis: The thermal resistance of copper roll shells is only 1/4–1/8 that of steel roll shells, and the heat flow per unit time is increased by 4–8 times. This accelerates the solidification speed of molten aluminum and allows higher casting-rolling speed.
- Experimental data: Under the same process parameters (casting temperature 680°C, roll gap 2 mm), the casting-rolling speed of copper roll shells can reach 10 m/min, while that of steel roll shells is only 4.2 m/min. The increase in speed directly doubles the production efficiency.
2. Simulation of Temperature Field and Thermal Stress
- Temperature distribution: Numerical simulation shows that the maximum surface temperature of the copper roll shell is lower than that of the steel roll shell by more than 85°C, and the temperature gradient is gentler, reducing the risk of thermal fatigue.
- Thermal stress control: The peak thermal stress of the copper roll shell is reduced by 30–50%. Its high thermal conductivity enables rapid heat diffusion, avoiding local overheating.
3. Improvement of Strip Quality
- Microstructure: The grain size of cast-rolled strip using copper roll shells is finer (average size 10–20 μm), with a high proportion of equiaxed grains and reduced segregation.
- Mechanical properties: The tensile strength is increased by 10–15%, while elongation remains stable, making it suitable for high-end aluminum foils and deep-drawing products.
III. Application Challenges and Solutions
1. Roll Sticking Problem and Prevention
- Causes: The high thermal conductivity of copper roll shells leads to excessively rapid solidification of molten aluminum. Insufficient interface lubrication easily causes aluminum sticking.
- Solutions:
- Pretreatment of roll surface: Spray a graphite layer (water: graphite emulsion = 40–50:1) before vertical setup to enhance lubrication.
- Process adjustment: Control the temperature of the front box (≈720°C) and reduce the strip exiting speed (≤1350 mm/min).
- Equipment modification: Install a torque monitoring system to adjust the rolling force balance in real time.
2. Roll Shell Preparation and Sealing Technology
- Centrifugal casting process: Beryllium bronze roll shells are formed by centrifugal casting to ensure compact structure.
- Sealing design: For copper-steel combined roll systems, water channel sealing is achieved by compressing rubber rings and nuts, preventing cooling water leakage.
IV. Industrialization Cases
1. Achievements
- High-speed casting and rolling experiment: On a Φ680 mm caster, copper roll shells successfully achieved a speed of 5 m/min, with strip thickness of 3 mm and no liquid leakage defects.
- Performance test: The yield strength of the strip reaches 85 MPa, and the elongation rate is 28–39%, meeting industrial standards.
2. Industrial Application Prospects
- Transformation of existing production lines: For example, in North China Aluminium Co., Ltd., after adopting copper roll shells, the speed of the Φ850 mm caster increased from 1.5 m/min to 3 m/min, doubling production capacity.
- Economic benefits: A single production line saves 20% of energy consumption annually, reduces 3–4 cold rolling passes, and lowers comprehensive cost by 15%.
V. Summary
Core Points
- High efficiency and energy saving: The casting and rolling speed of the copper roll shell is increased by 2.5 times, and unit energy consumption is reduced by 20%, aligning with the “dual carbon” goals.
- Quality upgrade: The strip has a uniform structure and excellent performance, suitable for high-demand fields such as lithium battery foils and aerospace.
- Mature technology: Through material optimization and process innovation, problems such as roll sticking and sealing have been solved, ensuring high reliability.
Future Directions
- Material innovation: Develop nano-reinforced copper composite materials to further improve high-temperature strength and wear resistance.
- Intelligent control: Integrate the Internet of Things technology to realize real-time regulation of the casting and rolling process and promote intelligent production.
The copper roll shell technology is leading the aluminum strip casting and rolling process into a new era of high speed, thin thickness, and high quality, injecting strong power into the aluminum processing industry!
Related News
Tel:
E-mail:
Address:
Economic Development Zone , Gongyi, China.
Message
Copyright © Zhengzhou Hengzhong Heavy Industry Machinery Manufacturing Co., Ltd.
Powered by :www.300.cn Supported IPV6 Privacy Agreement
SAF Coolest v1.3 设置面板 PVDSD-ZFUA-BAXAE-ZQQ
无数据提示
Sorry, there is no content in the current section!
You can view other columns or return to Home