HANI 1150mm Six-High (6-Hi) Reversing Cold Rolling Mill: Precision and Power for Advanced Strip Production
1. Product Overview
The HANI 1150mm 6-Hi Reversing Cold Rolling Mill represents the pinnacle of precision strip rolling technology. Engineered for unmatched control, flexibility, and efficiency, this single-stand reversing cold rolling mill is designed to produce high-quality cold-rolled strips with exceptional thickness accuracy and superior surface finish. Ideal for both ferrous and non-ferrous metals, this mill excels in medium to small batch production, pilot projects, and the manufacturing of high-value-added products where precise specification changes are frequent.
Unlike continuous tandem mills, the 6-high reversing cold rolling mill operates with a single work roll set, passing the strip back and forth through the roll gap. This reversible design offers unparalleled operational flexibility, allowing for quick product changeovers and the ability to achieve very high total reduction rates in a single machine—reportedly over 95% for certain carbon steel strips -7. The core of its performance lies in the advanced 6-high roll stack configuration, which provides superior solutions for controlling strip shape and profile compared to traditional 4-high mills.
For industries demanding top-tier precision in stainless steel, silicon steel, carbon steel, and specialty alloys, the HANI 6 hi reversing cold rolling mill is the robust and intelligent choice.
2. Key Technical Specifications & Design Features
The design of the 1150mm mill integrates proven robust mechanics with state-of-the-art control systems. The specifications below detail the capacity that makes this unit a powerhouse for precision rolling.
Table 1: Core Technical Specifications of the 1150mm 6-Hi Reversing Cold Rolling Mill
| Parameter Category | Specification | Details / Notes |
|---|---|---|
| Mill Type | Single-Stand, 6-High (6-Hi), Reversing | Also known as a Cold Reversing Mill (CRM) -4. |
| Work Roll Diameter | ~Φ260 – 280 mm (Typical) | Smaller work rolls enable the rolling of thinner gauges. Special “small roll diameter” designs are developed for high-deformation-resistance materials -3-9. |
| Intermediate Roll Diameter | ~Φ320 – 350 mm (Typical) | Axially shiftable for advanced profile and edge drop control. |
| Back-up Roll Diameter | ~Φ900 – 1000 mm (Typical) | Provides the rigidity needed for high rolling forces. |
| Roll Body Length | 1150 mm | Defines the maximum strip width capacity. |
| Max. Rolling Force | 10,000 kN | A key indicator of the mill’s power, allowing for high reductions -2. |
| Max. Rolling Speed | ≥ 730 m/min | Enables high production throughput -2. |
| Main Drive Motor Power | High-performance AC/DC | Configurable; often uses advanced multi-drive AC variable frequency speed regulation for stability -5. |
| Product Range (Carbon Steel Example) | Thickness: 0.2 – 0.8 mm; Width: 700 – 1000 mm -2 | Can be tailored. Technology exists to roll down to 0.12-0.15mm for thin-gauge products -7. |
| Thickness Tolerance | Extremely High Precision | Capable of achieving levels such as ±0.004mm on a 0.20mm base thickness -1. |
Advanced Design Integration:
Beyond the core specs, the mill’s superiority is built on integrated subsystems:
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Complete Line Configuration: The unit is typically supplied as a complete line including essential components like an uncoiler, a peeler/leveler, the main 6-high cold rolling mill stand, pinch rolls, a wraparound shear, two tension reels (left and right), and a coil discharge car -2. This ensures seamless material flow.
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High-Reliability Roll Stack: The heart of the mill features a rigid housing and a meticulously designed 6 hi roll stack structure. For challenging materials, innovations like high-reliability small-diameter roll systems are employed to prevent issues like roll skipping -9.
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State-of-the-Art Control Architecture: The mill utilizes a fully digital control system. This integrates hydraulic gap control (HGC), Automatic Gauge Control (AGC) for precise thickness, and comprehensive shape control systems, all managed through modern PLC and drive technology for maximum uptime and consistent quality -2-5.
3. Core Technological Advantages of the 6-Hi Reversing Design
The 6 hi reversing cold rolling mill is not merely an iteration but a significant evolution. Its advantages are rooted in its unique mechanics and control capabilities.
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Superior Shape and Profile Control: This is the primary advantage over a 4-high mill. The addition of a pair of intermediate rolls provides two extra powerful control actuators:
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Intermediate Roll Shifting (IRS): Axially moving the intermediate rolls allows for dynamic control of the roll gap profile across the strip width. This is exceptionally effective in managing edge drop (the thinning at the strip edges), a critical quality parameter, especially for electrical steels -4-6.
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Combined Bending Systems: Both work rolls and intermediate rolls can be equipped with positive/negative bending systems. When used in conjunction with IRS and segmented roll cooling, this allows for precise correction of complex shape defects like center buckles, edge waves, and quarter waves. Some advanced designs feature “smooth transition shape control technology” for even more stable operation -9.
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Unmatched Flexibility and Efficiency for Diverse Production:
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Quick Changeovers: The single-stand reversing cold rolling mill is perfect for short production runs. Switching between different grades, widths, or final thicknesses requires only a change in the rolling schedule (program), not extensive physical line modifications.
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Elimination of Intermediate Annealing: For many products, the high single-pass and total reduction capability (exceeding 90-95%) -7 allows producers to bypass costly and time-consuming intermediate annealing processes required by less powerful mills. This drastically reduces production cycle time, energy consumption, and operational costs.
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Pilot and Specialty Production: It is the ideal machine for R&D centers and mills producing high-strength steels, exotic alloys, or thin-gauge products where process parameters need frequent adjustment and close monitoring.
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Robustness for High Reduction Rolling: The six-roll configuration distributes the massive rolling forces (up to 10,000 kN) -2 through an extra set of rolls, reducing stress concentrations on the work rolls. This enables the use of smaller-diameter work rolls for biting and rolling thinner material, while the backup rolls ensure the overall stand rigidity is maintained for impeccable flatness.
4. Production Reference and Process Capabilities
The true value of the HANI 6-high reversing cold rolling mill is proven on the production floor. It solves specific, challenging production scenarios.
Table 2: Production Application Reference for a 1150mm 6-Hi Reversing Mill
| Product Category | Typical Entry Gauge | Target Exit Gauge | Key Process Highlight / Challenge Solved |
|---|---|---|---|
| Thin-Gauge Carbon Steel (e.g., for precise components) | 2.5 mm | 0.15 mm | Achieves a total reduction > 94% in one continuous rolling cycle, eliminating the need for an intermediate annealing step and shortening lead time -7. |
| High-Strength & Silicon Steel | 2.0 mm | 0.30 – 0.50 mm | The mill’s rigid frame and advanced shape control (bending + shifting) manage the high deformation resistance and strict flatness requirements essential for electrical steel performance -3-10. |
| Precision Tinplate Base | Not specified | 0.20 mm ±0.004 | Demonstrates the mill’s exceptional thickness control capability, producing strip with ultra-tight tolerances required for high-end packaging materials -1. |
| Stainless Steel & Special Alloys | Varies | Varies (Often thin specs) | The configuration allows for the use of smaller work rolls to reduce specific rolling pressure. Coupled with advanced process lubrication spray and oil retention technology-9, it ensures good surface quality on difficult-to-roll materials. |
Process Integration: A 6 hi reversing cold rolling mill can be the centerpiece of a compact, efficient production line. It can be paired with upstream acid cleaning or pickling lines and downstream annealing and skin-pass mills to form a complete processing route. Its precision and flexibility make it a cornerstone asset for manufacturers aiming for agile, high-quality production.
5. Frequently Asked Questions (FAQ)
Q1: What is the main difference between a 4-high and a 6-high reversing cold rolling mill?
A: The key difference is the addition of a pair of intermediate rolls between the work rolls and backup rolls in the 6-high cold rolling mill. This allows for Intermediate Roll Shifting (IRS), which dramatically improves the control over the strip’s cross-sectional profile and edge drop. A 4-high mill relies mainly on work roll bending and roll cooling, offering less precise shape correction capability.
Q2: What types of materials is this mill best suited for?
A: The HANI 1150mm 6-Hi mill is highly versatile. It is exceptionally well-suited for:
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Demanding Materials: High-strength steels (HSS), silicon electrical steels, stainless steel, and other alloys with high deformation resistance.
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Precision Products: Thin-gauge strips (down to 0.12mm and below), tinplate, and any product requiring very tight thickness and flatness tolerances.
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Flexible Production: Small to medium batch sizes where frequent product changes are needed.
Q3: How does the reversing process work, and is it less efficient than a continuous tandem mill?
A: In a reversing cold rolling mill, the strip is threaded through the rolls, rolled to a certain reduction, then the direction is reversed, and it is rolled again on the return pass. This repeats until the final thickness is achieved. While a continuous tandem mill is more efficient for very high-volume, single-product runs, the reversing mill is far more efficient for lower volumes and multiple products. It requires a much smaller capital investment, less floor space, and offers unmatched flexibility, making it overall more efficient for many market segments.
Q4: What are the critical maintenance points for a 6-high mill?
A: Primary maintenance focuses on the roll stack and hydraulic systems:
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Roll Management: Frequent inspection and regrinding of work rolls and intermediate rolls for surface finish and profile.
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Bearing and Seal Inspection: Ensuring the health of roll neck bearings and sealing systems, especially for intermediate rolls that both rotate and shift axially.
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Hydraulic System Integrity: The AGC, bending, and shifting systems depend on clean, leak-free hydraulic fluid at constant pressure. Regular fluid analysis and filter changes are crucial.
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Back-up Roll Inspection: While changed less frequently, backup rolls must be monitored for wear and surface condition.
Q5: Can this mill be automated?
A: Absolutely. Modern 6 hi reversing cold rolling mills like the one offered by HANI are designed for high automation. They feature fully digital drive systems, programmable logic controllers (PLCs), and sophisticated Human-Machine Interfaces (HMIs). Automation functions can include automatic roll changing (ARC), preset rolling schedules, fully automatic sequencing of passes, and integration with production planning systems. This reduces operator dependence and enhances consistency.
6. Why Choose HANI?
HANI brings decades of metallurgical expertise and engineering innovation to every 6 hi reversing cold rolling mill project. We don’t just supply machinery; we provide a total production solution tailored to your specific material and output goals. Our design incorporates field-proven technologies from leading industry research -1-7-9, ensuring reliability and cutting-edge performance.
Our 1150mm 6-High Reversing Cold Rolling Mill is built with premium components and features our proprietary control algorithms for stable, high-precision rolling. From initial consultation to installation, commissioning, and after-sales support, HANI is your committed partner in achieving manufacturing excellence.
Contact HANI today to discuss how our 6-high reversing cold rolling mill technology can optimize your production line for quality, flexibility, and profitability.
