Experimental testing of the technology of asymmetric cold rolling of a strip of high-carbon steel grades to exclude intermediate annealing operations

Abstract

In the production of cold-rolled strip from high-carbon steel grades with a thickness of 0.5–1.5 mm on continuous cold rolling mills, the technological process consists of 2–3 operating cycles "cold rolling – intermediate annealing", either of which significantly increases production costs and reduces productivity of technological process. One of the promising non-traditional ways to solve this problem is the technology of asymmetric rolling. Rolling with different circumferential speeds of work rolls, when both rolls are driven by two independent motors, is the most suitable way to implement the asymmetric rolling technology in industry. The mismatch of speeds of the work rolls will make it possible to reduce the rolling forces, increase the reduction ability of stands and, as a result, obtain a thinner strip without the use of intermediate annealing. This paper presents an experimental testing and a comparative analysis of the energy-power parameters of processes of symmetrical and asymmetric rolling, as well as an assessment of the possibility of reducing the number of operating cycles "cold rolling – intermediate annealing" in the production of strip from high-carbon steel grades in the PJSC MMK`s continuous five-stand mill 630. Data on the mode of operation of main electric drives of this mill during symmetric and asymmetric rolling are presented, some electrical and power parameters are calculated. A comparison of obtained results was carried out, which showed a significant reduction in rolling forces, total moments and powers, as well as the consumption of electrical energy during asymmetric rolling. Conclusions are drawn and directions for further research in this area are proposed.The research was supported by a grant from the Russian Science Foundation (agreement no. 22-49-02041 dated 09.03.2022) in terms of the development of asymmetric rolling modes and industrial experiments, as well as a mega-grant from the Ministry of Education and Science (agreement no. 075-15-2021-627 dated 08.06.2021 ) in terms of processing the results of industrial experiments.