What is the role of the intermediate roll in the rolling mill?

2025-09-05 13:00:03

The intermediate roll in the rolling mill mainly serves the following functions:

Improve the shape of the board

Add control measures: In multi roll rolling mills such as HC mills (high-performance shape control mills), CVC mills (continuous variable crown mills), etc., the intermediate roll can change the roll gap shape of the roll through axial movement or bending operations, thereby accurately controlling the transverse thickness distribution of the plate and strip. Compared with traditional work roll control, the addition of intermediate rolls increases the freedom and accuracy of shape control, which can more effectively suppress edge thinning and shape defects such as intermediate waves and edge waves in the plate and strip, and improve the quality of plate shape.

Uniform bearing pressure: The Intermediate roller can play a role in pressure transmission and uniform distribution between the working roller and the supporting roller. During the rolling process, uneven force distribution in the width direction of the strip can easily lead to bending deformation of the work roll. The presence of intermediate rollers can transfer the pressure of the supporting rollers more evenly to the working rollers, reduce the deflection of the working rollers, and make the rolling force more evenly distributed in the width direction of the plate and strip, thereby improving the plate shape.

Adapt to different rolling processes

Rolling force adjustment: In some special rolling processes, such as thin strip rolling or high-strength material rolling, a large rolling force is required. The intermediate roller can adapt to different rolling process requirements by adjusting its contact state with the working roller and the supporting roller, changing the transmission path and magnitude of rolling force. For example, when rolling ultra-thin strip, the bending force of the intermediate roll can be increased to reduce the deflection of the working roll, improve the stability of the rolling force, and achieve stable rolling of ultra-thin strip.

Tension control: In rolling processes such as continuous rolling mills, intermediate rollers can participate in tension control. By adjusting the speed and position of the intermediate rollers, the tension distribution of the plate and strip between each stand can be changed, ensuring the stability of the continuous rolling process and the quality of the plate and strip. For example, in a hot rolling mill, reasonable control of the speed and tension of the intermediate rollers can effectively prevent problems such as deviation and breakage of the plate and strip during the rolling process, and improve production efficiency and product quality.

Improve product quality

Reduce surface defects: The intermediate roller can serve to isolate and protect the working roller from the surface of the strip. During the rolling process, the work roll comes into direct contact with the plate and strip, which is easily affected by wear and oxidation, resulting in defects such as scratches and oxide skin indentation on the surface of the plate and strip. The presence of intermediate rollers can reduce the direct friction and contact between the work roller and the strip, lower the degree of wear of the work roller, thereby reducing the occurrence of surface defects on the strip and improving the surface quality of the product.

Control of plate thickness accuracy: By precisely controlling the position and pressure of the intermediate rollers, the size and shape of the roller gap can be adjusted more accurately, thereby achieving precise control of the thickness of the plate and strip. In high-precision plate and strip rolling, such as automotive plates, household appliance plates, etc., intermediate rollers play an important role in improving plate thickness accuracy and can meet the strict requirements of different users for product thickness tolerances.