| Parameter | Value |
|---|---|
| Equipment Name | 20-Hi 1150mm Cold Rolling Mill |
| Equipment Manufacturer | CFHI (China First Heavy Industries) |
| Manufacturing Year | 2018 |
| DC Motor Replacement Year | 2022 |
| Equipment Stop Production Date | December 2025 |
| Annual Production Capacity | 0.18 - 0.36 MTPA (180,000 - 360,000 tons/year) |
| Motor Type | Power | Quantity | Description |
|---|---|---|---|
| Main Motor | 1500 kW | 1 | Drives the main drive train of the mill |
| Recoiler Motor | 1500 kW | 1 | Drives the recoiler, provides coiling tension |
| Uncoiler Motor | 1500 kW | 1 | Drives the uncoiler, provides back tension |
| Roll Type | Specification (Dia. × Length) | Quantity | Function Description |
|---|---|---|---|
| Working Roll | Φ59/65 × 1320 mm | 2 (in 20-Hi system) | Direct contact with strip, performs rolling reduction |
| First Intermediate Roll | Φ99/103 × 1320 mm | 4 (in 20-Hi system) | Transmits rolling force to work rolls, assists driving |
| Second Intermediate Roll | Φ169/173 × 1320 mm | 6 (in 20-Hi system) | Further distributes rolling force, supports first intermediate rolls |
| Backup Roll | Φ320 × 1350 mm | 8 (in 20-Hi system) | Bears main rolling load, provides rigid support |
| Total Number of Mill Rolls | — | 20 rolls | Complete 20-high roll configuration |
| Number of Straightener Rolls | — | 5 rolls | Improves strip flatness |
| Parameter | Designed Value | Actual Value | Unit |
|---|---|---|---|
| Designed Rolling Material | MS (Mild Steel) | MS (Mild Steel) | — |
| Max Rolling Width | 1050 | 1050 | mm |
| Max Input Thickness | 3.0 | 3.0 | mm |
| Min Finished Thickness | 0.07 | 0.07 | mm |
| Thickness Reduction Ratio | 97.7% | 97.7% | — |
| Parameter | Value | Unit |
|---|---|---|
| Max Rolling Speed | 800 | m/min |
| Max Rolling Force | 3500 | KN |
| Screw-down Type | AGC (Automatic Gauge Control) | — |
| Coiling Method | Collapsible Drum | — |
| Parameter | Content |
|---|---|
| Electrical Control System Manufacturer | Schneider; Inovance |
| System Condition | Good, no missing parts |
| Spare Parts | Yes (specific list to be confirmed) |
Manufactured by CFHI (China First Heavy Industries) in 2018. CFHI is a leading heavy machinery manufacturer in China with extensive experience in metallurgical equipment.
Major core components (DC motors) were replaced in 2022, resulting in relatively short operating hours since replacement.
Equipment stopped production in December 2025, with approximately 7 years from manufacturing to shutdown. Actual operating time is limited, leaving substantial remaining service life.
Main Motor: Rated power 1500 kW, DC type, offering wide speed range, strong overload capacity, and fast dynamic response. Drives the main transmission of the mill.
Recoiler Motor: Also rated at 1500 kW, drives the recoiler to provide coiling tension, ensuring tight strip winding.
Uncoiler Motor: Rated 1500 kW, drives the uncoiler to provide back tension, preventing strip slack during rolling.
All three motors share the same power rating, simplifying system design and spare parts management. Total installed power reaches 4500 kW.
Working Roll:
Diameter: Φ59/65 mm (tapered or stepped design)
Barrel length: 1320 mm
Quantity: 2 (one top, one bottom in the 20-Hi system)
Function: Direct contact with the strip, applies rolling pressure. Key component for thickness reduction.
Material characteristics: Typically high-chromium steel or high-speed steel, offering high hardness and wear resistance.
First Intermediate Roll:
Diameter: Φ99/103 mm
Barrel length: 1320 mm
Quantity: 4 (two top, two bottom)
Function: Transmits rolling force from second intermediate rolls to work rolls. Some first intermediate rolls are driven to assist work roll rotation.
Second Intermediate Roll:
Diameter: Φ169/173 mm
Barrel length: 1320 mm
Quantity: 6 (three top, three bottom)
Function: Further distributes rolling force, prevents force concentration, and provides uniform load distribution to backup rolls.
Backup Roll:
Diameter: Φ320 mm
Barrel length: 1350 mm
Quantity: 8 (four top, four bottom)
Function: Bears the main rolling load, provides rigid support, reduces bending deflection of work rolls and intermediate rolls.
Backup rolls have the largest diameter and highest rigidity, enabling the 20-Hi mill to withstand high rolling forces.
Overall Advantages of the Roll System:
The 20-roll arrangement ensures more uniform rolling force distribution along the barrel length.
Small work roll diameter (only Φ59/65 mm) allows rolling of extremely thin strips.
Multiple backup rolls reduce elastic deflection of work rolls, improving shape control accuracy.
Number of straightener rolls: 5
Function: Straightens the strip after rolling, eliminating shape defects such as waves and warpage, improving strip flatness.
A 5-roll straightener is suitable for straightening thin to medium-thickness strips, forming a complete rolling-straightening line when combined with the 20-Hi mill.
Designed material: MS (Mild Steel)
Typical grades: Q195, Q235, SPCC, DC01, etc.
Application areas: Automotive structural parts, home appliance enclosures, hardware stamping parts, construction thin sheets, etc.
The mill is specifically optimized for mild steel cold rolling, with appropriate designs in deformation resistance, lubrication, rolling force settings, etc.
Maximum rolling width: 1050 mm
Designed and actual values match, confirming stable performance at this width.
Suitable for medium-width cold-rolled sheets, meeting downstream demand for wide strips.
Maximum input thickness: 3.0 mm
Designed and actual values match.
Rolling starts from 3.0 mm hot-rolled or pickled coils, reduced through multiple cold rolling passes.
Minimum finished thickness: 0.07 mm
Designed and actual values match.
Thickness reduction ratio as high as 97.7% (from 3.0 mm to 0.07 mm), demonstrating the exceptional thin-strip rolling capability of the 20-Hi mill.
0.07 mm falls into the ultra-thin strip category, suitable for precision stamping, battery foils, packaging materials, and other high-end applications.
Maximum rolling speed: 800 m/min
Classified as medium-to-high speed cold rolling mill.
At 800 m/min, the mill significantly increases hourly output while maintaining rolling quality and shape control.
Actual operating speed varies depending on pass number, material thickness, rolling force, and other factors.
Maximum rolling force: 3500 KN (approximately 350 metric tons force, or 357 tons force)
This rolling force is sufficient to reduce 3.0 mm mild steel down to 0.07 mm over multiple passes.
Due to the high rigidity of the 20-roll system, the mill can withstand high rolling forces despite the small work roll diameter—a key distinction from 4-high or 6-high mills.
Screw-down system type: AGC (Automatic Gauge Control)
The AGC system detects entry and exit thickness in real time and adjusts rolling force or roll gap accordingly, achieving closed-loop control of finished thickness.
When combined with high-precision thickness gauges (X-ray or isotope), thickness tolerances can be controlled within ±0.002 mm.
AGC is the core technology for high-precision rolling in modern cold rolling mills.
Drum type: Collapsible Drum
The collapsible drum allows the drum diameter to vary within a certain range, facilitating:
Threading of the strip head
Drum contraction for easy coil removal
Adaptation to different coil inner diameters (typically Φ508 mm or Φ610 mm)
The collapsible drum is typically hydraulically or mechanically actuated, offering reliable structure and convenient operation.
Manufacturers: Schneider + Inovance
Schneider: Globally recognized brand in automation and electrical control, providing PLCs, drives, servo systems, and other core components.
Inovance: Leading domestic industrial automation company, providing drives and control system integration.
System condition: Good, no missing components.
Spare parts: Included with the equipment (specific list to be confirmed).
The system supports multiple control modes including rolling force closed-loop, thickness closed-loop, tension control, speed control, etc., meeting high-precision rolling requirements.
Capacity range: 0.18 – 0.36 MTPA (180,000 – 360,000 tons per year)
Capacity depends on:
Annual operating hours (typically 6,000 – 7,200 hours/year)
Strip width and thickness (wide, thin strips yield lower output)
Number of passes and rolling speed
For a 1050 mm wide 20-Hi mill, 0.18 – 0.36 MTPA is a reasonable capacity range, suitable for mid-sized rolling enterprises or as a capacity expansion unit.
High precision: Minimum thickness 0.07 mm, tight thickness tolerances.
Wide width: Maximum width 1050 mm.
High efficiency: Maximum speed 800 m/min, annual capacity up to 360,000 tons.
High rigidity: 20-roll support structure, maximum rolling force 3500 KN.
Automation: AGC automatic gauge control, Schneider + Inovance electrical control system.
Flexible coiling: Collapsible drum for various coil diameters.
