650 mm Hot Rolling Line

1. Line Overview & Capabilities

This advanced hot rolling mills solution transforms 150-180mm carbon steel billets into precision strips (1.2-8.0mm thickness) at industrial scale. Engineered for continuous operation under ISO 50001 standards, it combines robust roughing with micro-tolerance finishing - achieving ±0.015mm thickness control while maintaining 12 m/sec exit speeds. The integrated V-H configuration ensures optimal width/thickness consistency across ASTM/JIS-grade materials.

2. Billet-to-Coil Transformation Process

Input Specifications

• Material: Carbon Steel (Q195-Q345)

• Dimensions: 450W × (150-180)T × 12,000L mm

• Entry Temperature: 1100°C ±20°C

Output Precision

3. Roughing Mill System (V-H-H-H-V-H-H)

Vertical Stands (2 Units)

• Roll Dimensions: Ø650 mm × 400 mm face

• Rolling Force: 150 tons/stand

• Drive Power: 500 kW × 2 motors (Siemens 1LG4)

• Technology: Hydraulic AWC width control

Horizontal Stands (5 Units)

• Roll Type: Two-high, Ø650 mm × 600 mm face

• Rolling Force: 500 tons/stand

• Drive Power: 1,250 kW × 5 (ABB AMZ)

• Reduction: 85% thickness reduction (180mm→27mm)

4. Finishing Mill System (V-H-H-V-H-H-H-H-H-H)

Vertical Stands (2 Units)

• Roll Dimensions: Ø550 mm × 220 mm face

• Rolling Force: 60 tons

• Drive Power: 300 kW × 2 (Yaskawa GA500)

Horizontal Stands (9 Units)

• Max Exit Speed: 12 m/sec

• Final Thickness: 1.2–8.0 mm (±0.015mm)

5. Core Engineering Innovations

Intelligent Control System

• Siemens TDC automation with predictive roll wear algorithms

• AGC + AWC coupling compensation for thickness/width stability

• Real-time thermal camber adjustment (ΔT ≤15°C)

Durability Enhancements

• Work rolls: High-chrome iron (HSD 700-800 hardness)

• Backup rolls: 70Cr3NiMo (UTS ≥1400 MPa)

• Quick-change cassettes (30-minute roll swap)

Energy Recovery Technology

• DC bus regeneration system (22% net power reduction)

• Hydraulic efficiency ≥92% through variable displacement pumps

• Heat recapture from descaling water (>500 kW/hr recovery)

6. Performance Validation

Quality Metrics

• Edge drop control: ≤0.8% of strip width

• Surface roughness: Ra ≤1.2 µm (skin-pass equivalent)

• Coil concentricity: ≤1.5 mm deviation at Ø1700mm OD

7. Safety & Compliance

• Certification: EN 10051 / PED 2014/68/EU

• Safety Systems:

• SIL-3 laser guards at roll gaps

• 0.3 sec emergency stop response

• Automated roll bite protection

• Maintenance:

• SKF vibration monitoring @ 10 kHz

• Embedded temperature sensors in bearing housings

8. Operational Economics

Efficiency Advantages

• 45 tons/hour throughput @ 8mm finished thickness

• 30% lower spare parts consumption vs. conventional hot rolling mills

• 18-month ROI at 10,000 tons/month production

Maintenance Optimization

• Online roll profile measurement system

• Dynamic lubrication adjustment based on load

• Cloud-based wear analytics (predictive replacement)