Investigating the Effectiveness of Roll Lubricants in Cold Rolling of Copper Bands in Industrial Two-High Rolling Mill 175 × 300

The article presents the results of the study on the influence of contact conditions, including the lubrication of rolls with industrial oil I20 (5%) and I40 (5%), on the deformation, force parameters, and power consumption during the cold rolling of 0.55-mm thick M0 copper alloy bands in a two-high rolling mill 175 × 300. Considering the rheological characteristics of copper M0 and the lubrication conditions of the rolls, a rational technology was designed for the rolling bands with a cross section of 0.55 × 20 mm from the semi-finished rolled products measuring 0.7 × 20 × 2000 mm. It was observed that using the roll lubrication with the industrial oil I20 or I40 at the 175 × 300 mill reduces the number of band rolling passes from three to two. Additionally, it ensured the specified accuracy of bands and reduced the equipment loads; it reduced the rolling force by 2.02 kN (9.16%) in pass 1, the rolling power by 0.083 kW (22.25%), and the rolling force by 2 kN (10.8%) in pass 2, simultaneously ensuring the specified accuracy of the band thickness at the mill outlet. The unevenness in the distribution of rolling forces along the band lengths when using the I20 lubricant decreased from 35.2% to 23.3% (in pass 1) and from 37% to 23.3% (in pass 2) compared with rolling in dry rolls. The unevenness of the deformation degree distribution along the band length when using the I20 lubricant decreased from 2.65% to 1.43% (in pass 1) and from 4.37% to 1.55% (in pass 2). The thickness distribution along the copper band length at mill outlet, when the rolls were lubricated with the industrial oil I20 or I40, was more uniform than that in dry rolls or those with water lubrication, and the longitudinal variations in the band thickness were the smallest and 0.01 mm when lubricated with I20 or 0.02 mm when lubricated with I40.