A Long-Term Technical Partner for Global Steel Producers
Company Overview
Founded in 2003, LMM GROUP Roll Manufacturing has grown into one of China’s most specialized producers of heavy-duty section mill rolls and roll rings. With over two decades of metallurgical expertise and continuous capacity expansion, the plant now operates with an annual output exceeding 90,000 metric tons, serving steel mills worldwide.
Rather than competing in low-end or small roll segments, LMM has strategically focused on medium to large-scale rolls, building a reputation for process stability, metallurgical integrity, and long service life. In recent years, the company has further expanded into hot strip mill work rolls and is actively entering the forged backup roll segment through its Phase II expansion project.
Core Product Portfolio
Specialization in Large, Heavy, and High-Precision rolling mill Rolls
1. Section Mill Rolls (Long Product Rolls)
Section mill rolls are LMM’s main products, widely used in H-beam, I-beam, channel, angle, and rail rolling lines.
- Diameter range: Ø600 – Ø1800 mm
- Single roll weight: 3 – 50 tons
- Design focus: Complex pass geometry and uneven stress distribution in section rolling
Through optimized alloy design and controlled heat treatment, significantly improves:
- Resistance to thermal cracking
- Wear resistance under high rolling loads
- Dimensional stability across long campaigns
These characteristics directly translate into longer roll life and fewer unplanned mill stoppages.
2. Roll Rings
Roll rings are produced primarily using centrifugal casting, ensuring high density and metallurgical soundness.
- Outer diameter: Ø550 – Ø1800 mm
- Minimum inner diameter: 300 mm
- Key advantage: Dense microstructure and strong bonding between working layer and core
This process is particularly suited for large-diameter roll rings where uniformity and fatigue resistance are critical.
3. Hot Strip Mill Work Rolls
LMMGROUP currently focuses on cast work rolls for hot strip mills.
- Applicable mill width: 1250 – 2250 mm
- Proven reference: Long-term supply to Gerdau (USA)
These rolls fully meet the operational requirements of modern high-capacity hot rolling lines, including surface quality, thermal stability, and consistent hardness depth.
Manufacturing Capability
Full Process Control from Melting to Final Machining
The plant is capable of producing components with:
- Maximum single-piece weight: 150 tons
- Maximum roll diameter: 2.5 meters
This capability is built on a robust and flexible equipment base.
Melting and Secondary Refining
15 medium-frequency induction furnaces:
3 t × 2 units
5 t × 3 units
8 t × 3 units
12 t × 5 units
20 t × 2 units
This configuration allows precise furnace matching to different roll sizes, ensuring:
- Stable superheat control
- Optimized energy efficiency
- 60-ton LF (Ladle Furnace) refining:
1.Argon stirring
2.Deoxidation and desulfurization
3.Precise alloy adjustment
This stage is essential for minimizing non-metallic inclusions and dissolved gases, especially for large-section rolls.
Advanced Centrifugal Casting
Centrifugal casting is the cornerstone of LMM’s roll performance.
11 centrifugal casting machines:
- 8 horizontal machines (standard rolls and roll bodies)
- 1 vertical machine (short and special geometries)
- 2 disc-type machines (large roll rings and disc-shaped parts)
This setup supports complex centrifugal castings up to 2.5 m in diameter, ensuring:
- Excellent bonding between shell and core
- Uniform working layer thickness
- Superior metallurgical integrity
Heat Treatment and CNC Machining
Heat treatment:
- 162 heat treatment furnaces
- Customized heating, soaking, and cooling curves for each roll type
- Precise control of hardness depth and microstructural transformation
Machining:
- Majority CNC-based equipment
- High consistency in complex pass geometry
- Improved surface finish and dimensional repeatability
Quality Assurance
Inspection to International Standards
LMMGROUP applies a defect-prevention philosophy, recognizing that even minor surface or internal defects can cause catastrophic rolling incidents.
- LISMAR Automatic Roll Inspection System (Netherlands)
- Integrated inspection methods:
1. Eddy Current Testing (ET):
2. surface micro-cracks, Ultrasonic Testing (UT):
3. internal defects, Surface Wave Testing (SW): near-surface integrity
On-Site Verification Example
During a recent technical audit, Conducted UT testing on an as-cast roll, prior to heat treatment. Results confirmed exceptional internal density and homogeneity, demonstrating that roll quality is fundamentally determined at the melting and casting stages, not “corrected” later by heat treatment.
Future Development
Phase II Expansion and Forged Backup Rolls
To address high-end market demand and reduce reliance on imported products, Liaoye is completing its Phase II expansion.
- Commissioning target: End of March (current year)
- Key new equipment:
1. 50-ton Electric Arc Furnace (EAF)
2. 100-ton VD Vacuum Degassing Furnace
The VD system enables ultra-low hydrogen and oxygen levels, which are mandatory for forged backup rolls.
New Capability
- Production of high-quality cast ingots
- Planned launch of forged backup roll manufacturing next year
- Ability to supply complete roll packages (work rolls + backup rolls) for plate and strip mills
Global References and Vision
LMM products are already in long-term service at leading steel producers, including:
- Hyundai Steel (Korea)
- POSCO Vietnam
- Gerdau (USA)
These references reflect stable performance under demanding industrial conditions. Building on its success in North America, Liaoye aims to become a long-term technical partner for steel producers seeking high-performance, long-life rolling solutions.
Conclusion
From its establishment in 2003 to its full-scale upgrade in 2026, LMM Moll Roll Manufacturing has remained committed to one principle:
“Data-driven metallurgy and quality-first manufacturing.”
Whether facing the challenge of 2.5-meter-diameter centrifugal casting or achieving ultra-clean steel through 100-ton VD refining, LMM continues to deliver reliable, globally competitive roll solutions for the modern steel industry.
What types of rolling mill rolls does Liaoye specialize in?
LMM specializes in medium to large-sized rolling mill rolls, primarily including section mill rolls, roll rings, and hot strip mill work rolls. The company focuses on rolls weighing 3 to 50 tons, heavy-duty industrial applications.
Why is centrifugal casting used for roll and roll ring production?
Centrifugal casting ensures a dense, uniform working layer and strong metallurgical bonding between the roll shell and core. This process significantly improves wear resistance, thermal crack resistance, and fatigue performance, especially for large-diameter rolls and roll rings.
What is the maximum roll size the plant can produce?
The plant can manufacture components up to 150 tons per piece, with a maximum Mill roll diameter of 2.5 meters. This capability supports large section mills and wide hot strip mills used in modern steel plants.
How does heat treatment affect roll performance?
Heat treatment controls the hardness profile, microstructure, and residual stress distribution of the roll. With over 160 heat treatment furnaces, customized heating and cooling curves are applied to each roll type, ensuring stable performance and long service life.
What inspection methods are used to detect roll defects?
The plant uses an automatic LISMAR roll inspection system, integrating:
- Eddy Current Testing (ET) for surface cracks
- Ultrasonic Testing (UT) for internal defects
- Surface Wave Testing (SW) for near-surface integrity
- This multi-layer inspection approach meets international steel mill standards.
Which steel producers currently use these rolls?
LMM Mill rolls are in long-term service at international steel producers such as Hyundai Steel, POSCO Vietnam, EVRAZ Group, and Gerdau (USA). These references demonstrate stable performance under demanding rolling conditions.
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