20-hi Rolling Mill Analysis

The 20-hi rolling mill, as a typical representative of multi-roll cold rolling mills, with its unique roller configuration and precise control capabilities, has become a core equipment in the field of metal thin strip processing. The "20-hi" in its name refers to a composite roller system composed of 20 working rollers and support rollers. Through multiple layers of roller bodies to distribute the rolling pressure, it can achieve stable production of extremely thin strips with a thickness of 0.05mm or less.
Core structural features
Composite roller system design
It adopts a four-layer arrangement of 1-2-3-4 type (1 working roller + 2 intermediate rollers + 3 backing bearings + 4 support frames), and dynamically adjusts the roller gap shape through a hydraulic bending roller system to compensate for elastic deformation during the rolling process. The main motor power is usually 3000-6000kW, and it is combined with a fully digital DC/AC transmission system.
Precise control system
It is equipped with automatic thickness control (AGC) and plate shape detector, with closed-loop control accuracy of ±0.5μm. Modern models integrate AI algorithms, which can predict the thermal crown of the rollers in real time. For example, after being applied in a certain steel mill, the plate difference of the strip became from 3% to 0.8%.
Typical application scenarios
Special alloy processing: titanium alloys, niobium alloys, etc. difficult-to-deform materials rolling
Electronic industry: lithium battery copper foil (6-8μm), flexible circuit board base material
Precision machinery: clock spring, medical stents, etc. ultra-thin component raw materials