Views: 100 Author: Site Editor Publish Time: 2026-06-13 Origin: Site
Forged steel cold rolling rolls (work rolls, intermediate rolls, backup rolls) are manufactured via a three-stage smelting process: electric furnace melting, vacuum refining and electroslag remelting (ESR). They undergo a series of hot and cold working procedures including forging, high-temperature diffusion treatment, normalizing, spheroidizing annealing, hydrogen degassing, as well as subsequent quenching and tempering, dual-frequency quenching, cryogenic treatment and machining to meet the service requirements of rolls for metal cold rolling.
Forged steel cold rolling rolls are mainly applied as work rolls and intermediate rolls for various continuous cold rolling mills and single-stand cold rolling mills for ferrous metals; work rolls for cold and hot skin pass mills; work rolls and backup rolls for small-sized cold rolling mills; and cold rolling work rolls and backup rolls for non-ferrous metal rolling mills.
ETERNAL's high-quality cold rolling rolls adopt superior production processes and strict quality control systems. They are fully compatible with cold rolling lines of world-renowned manufacturers, including SMS group (Germany), Achenbach (Germany), Danieli (Italy), Primetals Technologies (UK) and Hitachi (Japan). The applicable equipment covers tandem cold rolling mills, six-high UC-MILL, aluminum foil rolling mills, precision stainless steel rolling mills and other types of rolling units.
Currently, the mainstream materials for forged steel cold rolling rolls include Cr2, Cr3, Cr5, Cr6, semi-high-speed steel and high-speed steel grades. The roll body hardness varies slightly for rolls used in different rolling mills. The recommended roll body hardness (HSD) is shown in the table below.
| Rolling Mill | Work Roll | Intermediate Roll | Leveling Roll | |
| Single-stand cold rolling mill | 88-94 | 75-85 | 94-98 | |
| Continuous cold rolling mill | 93-97 | 75-85 | 94-98 | |
| Non-ferrous metal rolling mill | 92-98 | 75-85 | 95-100 | |
| Aluminum foil work roll | 100-105 | |||
The Cr2 series is an early-developed material for cold rolling rolls with a chromium content of approximately 2%. The hardened layer depth is no more than 15 mm for work rolls and 25 mm for intermediate rolls. Its typical grades include 86CrMoV7, 8Cr2MoV, 9Cr2Mo and 9Cr2MoV,etc.
Advantages: Low retained austenite content and relatively stable microstructure. The shallow hardened layer effectively prevents deep spalling.
Disadvantages: Due to the limited hardened layer depth, work rolls made from this series usually require 1 to 2 re-quenching treatments. The low alloy content results in moderate wear resistance.
Developed on the basis of Cr2 series, the Cr3 series features a chromium content raised to around 3%. The increased alloy elements enhance hardenability, delivering a hardened layer generally over 25 mm deep, with a maximum depth of 30 mm. Common grades cover 8Cr3Mo, 8Cr3MoV, 9Cr3Mo, 9Cr3MoV, 32Cr3Mo1V, MC3A, MC3B, MC3C and MC3D,etc. It is the most widely adopted forged steel roll material for small and medium-sized cold rolling production lines.
Advantages: Higher alloy content boosts wear resistance by roughly 30% compared with the Cr2 series. The deep hardened layer eliminates the need for re-quenching in most cases.
Disadvantages: The thick hardened layer is prone to deep spalling in the event of severe rolling accidents.
As a new grade with deep hardening capacity, the Cr5 series has a chromium content of about 5%. Its hardened layer depth exceeds 45 mm and can reach up to 50 mm. Main grades include 8Cr5Mo, 8Cr5MoV, 9Cr5Mo, MC5A, MC5B, MC5C and MC5D,etc. Currently, it is the dominant core material widely used across the global cold rolling industry.
Advantages: The high chromium content nearly doubles the wear resistance compared with Cr2 cold rolls. Fine and uniformly distributed carbides deliver excellent anti-damage performance. The extra-deep hardened layer allows the roll to be used down to its scrap diameter without re-quenching.
Disadvantages: Deep spalling may occur if surface defects are not removed promptly.
The Cr6 series is a newly developed cold roll material in recent years, with a chromium content of approximately 6%. A typical grade is 9Cr6MoV,etc. Abundant chromium converts all carbides in the microstructure into phases with higher microhardness and superior wear resistance. Meanwhile, the hardness drop within the working layer is minimized with increased chromium content. This material is primarily used for work rolls rolling high-grade automotive sheet and home appliance sheet.
Semi-high speed steel is a new multi-alloy forged steel for cold rolling rolls. Based on Cr5 and Cr6 materials, it is further alloyed with trace elements such as tungsten, molybdenum, vanadium and niobium. Its hardness decreases mildly as tempering temperature rises, accompanied by the precipitation of a large number of tertiary carbides for dispersion strengthening, presenting remarkable secondary hardening effect. The optimized microstructure greatly improves wear resistance and anti-damage capability. It is the preferred roll material for processing hard-to-roll metals including electrical steel, stainless steel and hot-rolled aluminum.
For cold rolling of small ordinary sheets with a limited budget: Prioritize Cr3 series for the best cost performance.
For cold production lines and low-load rolling with stability as the priority: Adopt the traditional Cr2 series.
For rolling of precision stainless steel and regular high-end sheets: Cr5 series is the industry’s preferred choice.
For high-grade hard-to-roll sheets such as automotive sheets and home appliance sheets: Select dedicated Cr6 series.
For high-hardness metals including electrical steel and stainless steel: Choose semi-high-speed steel.
