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Product Description
In a multi-high rolling mill, the back-up roll is the foundation of rigidity and precision. These massive rolls provide the critical support necessary to prevent the smaller work rolls from deflecting under millions of tons of rolling force. The reliability of a back-up roll is paramount; its failure can lead to catastrophic damage and extended, costly downtime.
Yile Machinery engineers and manufactures world-class forged back-up rolls, built to deliver exceptional service life, superior spalling resistance, and unwavering performance in the most demanding hot and cold rolling applications.
Due to the immense operational stresses, back-up rolls can only be made from forged steel. This process is fundamental to ensuring their structural integrity and longevity.
Superior Metallurgical Purity: We start with large-scale steel ingots (e.g., 9Cr2, 86CrMoV7, 70Cr3NiMo) that are refined through processes like electroslag remelting (ESR) to ensure ultra-low impurities.
Forged for Maximum Toughness: The ingot is forged under immense pressure, which refines and aligns the steel's grain structure. This process eliminates internal voids and creates a component with exceptional fatigue resistance and toughness, capable of withstanding extreme shock loads.
A back-up roll must have a dual personality: a hard, wear-resistant surface and a tough, ductile core and neck. Our specialized heat treatment achieves this balance perfectly.
Full Body Quenching & Tempering: The entire forged roll undergoes a comprehensive heat treatment to develop the foundational strength and toughness required.
Differential Hardening of the Roll Barrel: The working surface (the barrel) is then subjected to a secondary hardening process. This creates a deep, uniformly hard layer (HSD 65-80 / approx. HRC 45-60, depending on material and application) that is highly resistant to wear and indentation from the work roll.
High Spalling Resistance: The combination of a tough core and a hard surface results in excellent resistance to spalling (surface cracking and flaking), which is the primary failure mode for back-up rolls.
Every surface of a back-up roll is a critical engineering interface. We utilize heavy-duty CNC lathes and grinders to achieve the required precision on these massive components.
Roll Barrel: Ground to a precise profile and surface finish to ensure uniform contact with the work roll.
Bearing Journals (Necks): Precision ground to tight tolerances for a perfect fit within the bearing chocks, ensuring smooth rotation and long bearing life.
Dynamic Balancing: All back-up rolls are dynamically balanced to eliminate vibration during high-speed operation, protecting the mill stand and associated components.
Our forged back-up rolls are the definitive choice for providing support in:
Hot Strip Mills
Plate Mills
Cold Rolling Mills (4-Hi, 6-Hi, Cluster Mills)
Temper Mills
We manufacture rolls for processing both ferrous (carbon steel, stainless steel) and non-ferrous (aluminum, copper) metals.
Partner with us for your next replacement or OEM back-up roll. Submit your technical drawings and operational parameters, and our engineering team will provide a comprehensive proposal for a roll designed for maximum tonnage and reliability.
