Material Grade: Cr3, Cr5

Hot & Cold Rolling Mill Alloy Steel Backup Rolls (Cr3 & Cr5 Series)

Engineered for high-rigidity applications requiring exceptional resistance to contact fatigue and thermal shock. The Cr series utilizes a high-chromium alloy steel matrix (up to 5.40% Cr) to provide a stable support structure for work rolls, helping to maintain precise strip profiles under intense contact pressure in hot and cold flat rolling.

By Material

By Application

By Tooling

Key Mill Applications (Recommended Stands)

Hot Strip & Heavy Plate Mill Backup Rolls

Applicable Grades: Cr3, Cr5

Focus: Designed as high-performance backup rolls for hot strip mills and heavy plate mills. Exhibits extreme fatigue strength and superior anti-spalling properties to safely withstand massive rolling tonnage without shell peeling.

Cold Strip & Skin Pass Mill Backup Rolls

Applicable Grades: Cr5

Focus: Engineered for high-precision backup rolls in cold rolling mills and temper/skin pass mills. Excellent depth of hardness layer ensures minimal elastic deformation, maintaining long-term strip flatness and thickness control.

Heavy Reduction Hot Roughing Stands

Applicable Grades: Cr3

Focus: Optimized for initial heavy roughing work rolls in hot strip and medium plate lines. High structural integrity and thermal shock resistance successfully prevent thermal cracking during continuous slab reduction.

Chemical Composition & Physical Properties

We optimize the deep-hardening characteristics and contact fatigue life through precise micro-alloying with Molybdenum and Vanadium. The metallurgical specifications for the Cr series are detailed below:

Code (代码)	C	Si	Mn	Cr	Ni	Mo	V	Hardness (Barrel HSD)
Cr3	0.20-0.50	0.20-0.70	0.50-1.30	2.40-3.50	≤ 0.80	0.30-0.60	0.05-0.20	58-63
Cr5	0.30-0.55	0.20-0.70	0.30-1.10	4.70-5.40	≤ 0.50	0.50-0.85	0.15-0.40	68-73

* P ≤ 0.08, S ≤ 0.05.
* Neck Hardness: ≤ 40 HSD for both grades.

Metallurgical Excellence

Why do DURON Cr Series rolls deliver reliable support in flat rolling?

Enhanced Contact Fatigue Resistance : The high-chromium content and optimized heat treatment yield a microstructure capable of sustaining prolonged cyclic loads. This effectively delays the onset of surface spalling and maintains the integrity of the roll barrel under high nip-pressure.
Rigidity & Deflection Control : Formulated for high elastic modulus, the Cr series provides the necessary stiffness to resist bending under heavy mill loads. This is a critical factor in ensuring accurate strip crown control and minimizing edge-drop in precision rolling.
Secondary Hardening Effect : The inclusion of Molybdenum and Vanadium promotes secondary hardening during the tempering process. This contributes to a stable hardness profile throughout the usable working layer, helping to provide consistent support for the work rolls across the entire campaign.

Manufacturing Control & Inspection

100% Non-Destructive Testing

Every roll undergoes rigorous Ultrasonic Testing (UT) at the working layer and bonding zone to eliminate internal voids and ensure structural integrity under heavy loads.

Precision CNC Machining

Roll necks and barrel profiles are machined using heavy-duty CNC equipment, strictly adhering to your drawing's dimensional and runout tolerances for perfect bearing fitment.

Metallurgical Verification

Chemical compositions are analyzed via spectrometer pre-pouring, and multi-point hardness mapping is conducted post-heat treatment to guarantee the specified hardness gradient.

Quality Traceability

All dispatched rolls are accompanied by a comprehensive inspection certificate, documenting chemical composition, hardness distribution, and UT reports.