Theoretical and experimental analysis of the rolling process of bimetallic rods Cu-steel and Cu-Al

In this study, the authors present the results of their theoretical and experimental analysis of the rolling process of bimetallic rods in stretching passes. The bimetallic rods had different ratios of the yield stress between components. The original rods were round (21.7 mm diameter) steel and aluminium rods, covered with 2.8 mm copper layer. A numerical model for hot stretching passes rolling was proposed. In the model, the deformation of a bimetallic material was analysed by three-dimensional rigid–plastic finite-element method. The model simulated metal flow during rolling of bimetallic rods in round–oval series. The results of the experiments were compared with the finite-element calculations of the stress distribution and spread of Cu-steel and Cu-Al rods in the deformation zone. The analysis demonstrated that an appropriate selection of shape and size of oval pass allows production of even distribution of the copper layer in the bimetallic roll products. The results of comparison of calculated spread and experimental data confirmed good ability of proposed mathematical model, that is recommended for roll pass design at rolling of bimetallic rods.