Owing to the specific demands on cold rolls, the production of these tools is a special field among the applications for cold-work steels.

Deutsche Edelstahlwerke manufactures cold rolls from the blank to the ready-to-use roll. For cold rolls and blanks, Deutsche Edelstahlwerke supplies steel grades that have been specifically developed for this application and whose analytical composition has been optimised to suit the special requirements and production of the rolls.

• 2-3 % Cr steels. As a result of their alloying state, these steels have a balanced ratio of hardness, effective hardening depth and toughness. These steels are used exclusively for surface-hardened rolls. For special requirements, Deutsche Edelstahlwerke also offers all types in remelted form.
• 5% Cr steel. Compared to the 2-3% Cr steels, this steel has a higher compressive strength. It can be used in completely through-hardened or partially hardened form.
• 7-12% Cr steels.These steels are predominantly used for through-hardened rolls. In special cases, however, Deutsche Edelstahlwerke can also produce partially hardened rolls made of these steels.

Applications

Cold rolls are used for cold-forming low and high-alloy steels and non-ferrous metals. Deutsche Edelstahlwerke supplies ready-to-fit work and back-up rolls for all applications. Auxiliary and straightening rolls are also produced to customer specifications on special request.

Delivery range

• Wide strip rolls for the steel industry: for this application, Deutsche Edelstahlwerke supplies quenched and tempered blanks in pre-turned condition, and also in drilled condition on request
• Narrow and medium-wide strip rolls for the steel industry: work and back-up rolls made of 2-3% Cr steel in ready-to-fit condition; auxiliary and straightening rolls on request
• High-alloy steel strip: Deutsche Edelstahlwerke supplies work rolls, inner and outer intermediate rolls for multiple-roll stands. The work rolls are made of 12% Cr steel or HSS, the intermediate rolls being made of 5-7% Cr steel.
• Non-ferrous metals: ready-to-fit working rolls made of 2-3% Cr steel for strip and foil; back-up rolls on request; blanks on request
• Hot or cold-straightening rolls for straightening plate and strip: material selection and design in accordance with customer specifications or requirements

Production

All cold rolls supplied by Deutsche Edelstahlwerke are manufactured entirely in-house - from steel production, hot-forming and heat treatment, all the way to machining. The metallurgical and technological properties of the steels used can thus be accurately tailored to the specific requirements. The use of special smelting reduction processes, such as electroslag remelting (ESR) or vacuum arc remelting (VAR), ensures compliance with the requirements regarding the surface quality, purity and isotropy of the material.

Modern forging units guarantee thorough forming with high compaction of the core zone. The rolls are already contour-forged close to the finished dimensions during hot-forming by using the 33 MN forging press and the RF70 forging machine. The subsequent heat treatment thus ensures thorough quenching and tempering, even of the thinner journal areas.

The roll blanks are pre-machined in quenched and tempered or annealed condition.

For treating the finish-machined rolls, Deutsche Edelstahlwerke has hardening units for inductive surface hardening and soaking pits for through-hardening of the steels.

The rolls are machined on the latest lathes, millers and grinders, permitting compliance with extremely close tolerances.

Extensive testing of every roll guarantees consistently high quality of the products supplied.

A team of qualified engineers is at your disposal to deal with enquiries and provide targeted advice on applications.