6-Hi 1150mm Cold Rolling Mill

1. Equipment Overview
This is a 6-Hi 1150mm six-high reversible cold rolling mill, manufactured by Antai in 2010. This is a wide-width high-speed cold rolling mill, specifically designed for high-speed precision cold rolling of pickled hot-rolled coils. The 6-Hi configuration consists of 2 work rolls, 2 intermediate rolls, and 2 backup rolls. Compared to 4-Hi mills, it offers superior shape control capability, lower rolling force requirements, and a wider thickness application range—representing an advanced configuration for modern wide-width cold rolling mills.

2. Manufacturer Background
Antai is a significant enterprise in China's metallurgical equipment manufacturing sector, with deep technical expertise in the R&D and production of large-scale cold rolling mills, 6-Hi mills, temper mills, and other high-precision cold rolling equipment. The Antai brand enjoys high market recognition in the cold rolling industry, with products known for large-scale design, high speed, and high precision.

3. Core Highlights — Advanced 6-Hi Structure + High-Speed Wide-Width Capability
The core highlights of this equipment lie in the combination of its advanced 6-Hi structure and high-speed wide-width capability:

• 6-Hi structure: Intermediate rolls can perform axial shifting, effectively compensating for roll bending deformation caused by rolling force, achieving more precise shape control;

• Wide 1050mm format: Covers mainstream cold-rolled strip width specifications;

• High speed 800m/min: A medium-to-high speed configuration among 1150mm-class 6-Hi mills, offering high production efficiency;

• Ultra-thin finished gauge 0.15mm: Rolling from 3.5mm to 0.15mm represents a total reduction of 95.7%, demonstrating the powerful thin-gauge rolling capability of the 6-Hi mill;

• Pickled hot-rolled coil input: Can directly use pickled hot-rolled coils for cold rolling, offering strong raw material adaptability.

4. Main Motor System — Dual Motor High-Power Drive
The mill is equipped with 2 main motors, each rated at 1250kW, for a combined total of 2500kW. The brand, voltage, and speed of the main motors are not detailed in the technical data sheet. Dual motor drive is the standard configuration for reversible mills—during the reversing rolling process, the strip passes through the mill in multiple passes, with the coiler and uncoiler swapping roles after each pass, requiring two independent drive systems. The symmetrical configuration of 2 x 1250kW motors ensures balanced power delivery in both rolling directions, with 2500kW total power representing an ample configuration for 1150mm-class 6-Hi cold rolling, sufficient for high-speed rolling of pickled hot-rolled coils.

5. Recoiler and Uncoiler Systems

• Recoiler: Equipped with 4 x 618kW motors, totaling 2472kW. The four recoiler motors may correspond to a dual-coiler or segmented drive solution, ensuring stable recoiler operation under high-tension, high-speed rolling conditions, guaranteeing tight and neatly wound finished coils while preventing interlayer slippage and coil loosening.

• Uncoiler: Equipped with 1 x 300kW motor, responsible for smooth pay-off of pickled hot-rolled mother coils, providing continuous and stable strip input for the cold rolling process.

• Coiling method: Adopts a collapsible drum, which retracts during coil unloading for easy removal of finished coils, improving unloading efficiency and operational safety.

6. Mill Type — Advanced 6-Hi Configuration
This equipment is a 6-Hi (six-high) cold rolling mill, consisting of 2 work rolls, 2 intermediate rolls, and 2 backup rolls. The 6-Hi configuration offers the following significant advantages over 4-Hi mills:

• Superior shape control: Intermediate rolls can perform axial shifting, effectively compensating for roll bending deformation caused by rolling force, achieving more precise shape control;

• Thinner finished gauges: Smaller work roll diameters, supported by intermediate rolls, enable rolling of thinner gauges (minimum 0.15mm);

• Higher rolling speeds: Better roll system stability, suitable for high-speed rolling (maximum 800m/min);

• Wider thickness application range: Capable of handling a broad range of specifications from thick to thin on the same equipment.

7. Roll Systems

• Work Roll: Specification Φ220/190×1150mm—new roll diameter 220mm, replaced when worn to 190mm, barrel length 1150mm. Small-diameter work rolls help reduce rolling force and enable thin-gauge rolling while ensuring strip surface quality;

• Intermediate Roll: Specification Φ350/320×1100mm—new roll diameter 350mm, replaced when worn to 320mm, barrel length 1100mm. Intermediate rolls can perform axial shifting and are the key actuators for shape control;

• Backup Roll: Specification Φ950/890×1050mm—new roll diameter 950mm, replaced when worn to 890mm, barrel length 1050mm. Ultra-large-diameter backup rolls provide robust rigid support to the work rolls and intermediate rolls, ensuring minimal roll system deformation under high rolling forces;

• Screw-down System: Adopts AGC (Automatic Gauge Control) hydraulic screw-down—featuring fast response and high control precision, capable of real-time roll gap detection and adjustment during high-speed rolling, ensuring finished strip thickness tolerances are controlled within extremely tight limits across the entire length.

8. Designed Rolling Parameters

• Designed rolling material: Pickled Hot-Rolled Coil, covering 08A1, Q195, SPHC, SPHD, SPHE, STW, and other low-carbon, deep-drawing, and structural steel grades;

• Maximum designed input thickness (entry): 3.5mm;

• Minimum designed finished thickness (exit): 0.15mm—rolling from 3.5mm to 0.15mm represents a total reduction of 95.7%, demonstrating the powerful cumulative deformation capability of the 6-Hi mill;

• Maximum designed rolling width: 1050mm—with work roll barrel length of 1150mm, the effective rolling width of 1050mm leaves sufficient margin;

• Actual maximum rolling width used by the original owner: 1050mm—consistent with design;

• Actual maximum input thickness used by the original owner: 3.5mm—consistent with design;

• Actual minimum finished thickness used by the original owner: 0.15mm—consistent with design;

• Maximum rolling speed: 800m/min;

• Maximum rolling force: 8000kN (approximately 800 metric tons of force).

9. Maximum Rolling Speed — 800m/min High-Speed Advantage
The 800m/min maximum rolling speed is an important performance indicator of this equipment. In cold-rolled strip production, rolling speed directly determines shift output and production efficiency. The 800m/min high-speed capability意味着:

• Extremely high production efficiency: Shift output far exceeds low-speed mills, suitable for high-volume continuous production;

• Superior thickness accuracy: High-speed rolling combined with AGC automatic thickness control enables more stable thickness tolerance control;

• Excellent surface quality: High-speed rolling contributes to obtaining smoother strip surfaces;

• 800m/min represents a medium-to-high-speed configuration for 1150mm-class 6-Hi reversible cold rolling mills, reflecting high-level design and manufacturing capability.

10. Maximum Rolling Force — 8000kN of Power
The 8000kN (approximately 800 tons of force) maximum rolling force provides ample deformation capability. Pickled hot-rolled coils have lower deformation resistance than stainless steel, but the large cumulative reduction between 3.5mm entry and 0.15mm exit (95.7%) requires substantial rolling force, and high-speed rolling conditions require sufficient rolling force to ensure thickness accuracy and shape quality. The 8000kN rolling force configuration fully meets these requirements, ensuring the equipment maintains stable thickness accuracy and shape quality when rolling thicker materials and higher-strength grades.

11. AGC Hydraulic Screw-Down System
This mill employs an AGC (Automatic Gauge Control) hydraulic screw-down system, rather than traditional electric screw-down. AGC hydraulic screw-down offers the following significant advantages:

• Fast response: Completes roll gap adjustment in milliseconds, adapting to thickness fluctuations during high-speed rolling;

• High control precision: Enables micron-level roll gap adjustment, ensuring finished strip thickness tolerances are controlled within extremely tight limits across the entire length;

• Strong dynamic adjustment capability: Real-time compensation under conditions such as entry thickness fluctuations, speed changes, and tension fluctuations, ensuring stable exit thickness;

• Improved product quality: AGC is a core configuration of modern cold rolling mills, directly determining product thickness accuracy and quality stability.

12. Electrical Control System — Beizheng and Siemens
The mill's electrical control system is supplied by Beizheng and Siemens, with specific configuration details to be confirmed. Beizheng is a well-known Chinese provider of metallurgical drive and automation control systems, with extensive engineering application experience in cold rolling, hot rolling, pickling, and other metallurgical fields. Siemens is a globally leading brand in industrial automation and drive control, with world-class technology in high-speed cold rolling control. According to the technical data sheet, the electrical control system is in good condition (Yes) with no missing components—meaning the mill's automation control system, drive control system, AGC, PLC, sensors, and associated equipment are all complete and functional.