A newly-built double cold reduction (DCR) mill supplied by Primetals Technologies has commenced operation at the Shanghai works of Chinese steel producer, Baoshan Iron & Steel.

The DCR mill is designed to process 205kt/yr (metric tons) of cold strip and is part of the Chinese steelmaker’s Tinplate Product Structure Optimisation Project. It may be run in both reduction/temper and temper mode, and the processed strip will be used for the production of beverage cans, metal caps and electrical components.

Primetals Technologies received the order in December 2016.

The mill consists of a two-stand UCM and is designed to perform double-cold reduction as well as one-stand temper rolling.

In the DCR process, the annealed strip, after reduction in a tandem cold mill, is reduce rolled on the No. 1 stand and temper rolled on the No. 2 stand. This process imparts the strip with its prescribed mechanical strength. In stand No. 1, work rolls with two different diameters can be used. In one-stand temper rolling, the strip is temper rolled in stand 2 to the prescribed elongation ratios to obtain the desired mechanical characteristics.

The DCR mill processes strip produced by a PLTCM (pickling line and tandem cold mill). Entry strip gauges are between 0.17 mm and 0.55 mm. Exit gauges range from 0.12 mm to 0.36 mm. Strip width may vary from 700 to 1,230 mm. At a coil diameter of 2,000 mm, maximum coil weight amounts to 24.15 tons. Steel grades include DR7 to DR10.