Principle
In a 3-roll stand, three rolls offset by 120° engage the stock simultaneously. Compared with conventional two-roll stands, the cross-section is deformed more uniformly, which benefits dimensional accuracy, roundness and surface quality.
Arranged in blocks of several consecutive stands, 3-roll technology produces bars and wire rod with tight tolerances. KOA-NewTec offers expert services for 3-roll blocks, from mechanical design to technological implementation in the mill.
Configurations and equipment
RFB (reducing-finishing block)
Installed at the end of the mill, the RFB rolls the stock to its final size and largely determines the tolerances of the finished product.
IRB (intermediate-reducing block)
Installed in the intermediate mill, the IRB prepares the stock precisely for the downstream finishing stands.
Mechanical roll adjustment
Robust, proven adjustment for stable rolling programmes with few size changes.
Servo-hydraulic roll adjustment
Fast, precise adjustment, even under load, for frequent size changes and active dimensional control.
Optical roll setting
Simple, reproducible roll setting with an optical system that shortens set-up times.
Closed-loop control
Measurement of dimensions and surface downstream of the block with direct feedback to the roll adjustment.
Benefits
How large the benefits are in each case depends on product programme, design and integration into the existing mill.
Tighter tolerances
Uniform deformation enables high dimensional accuracy and roundness of the finished product.
Flexible rolling programme
With adjustable rolls, different finished sizes can be rolled with the same pass design.
Less set-up effort
Fewer roll changes and faster setting increase plant availability.
Assured quality
Integrated measuring and inspection detect deviations before scrap is produced.
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