Investigation of effective parameters in the sandwich and conventional rolling process of the thin steel sheet using the finite element method

In this paper, sandwich rolling of a thin steel sheet with aluminum layers and its conventional rolling process have been investigated and compared. Stainless steel SUS304 for the sheet and aluminum 1050 for the output layers have been used. Both the rolling procedures have been analyzed by the finite element (FE) method with work harden material behavior and FE model has been verified using the experimental results. Then strain, pressure distribution, required rolling force and moment for the rolling processes have been compared. The affect of the sandwich rolling parameters such as deformation ratio, tension forces, friction factor and roll radius have been investigated. Results show that the FE model is in good agreement with the experimental results. Uniformity of the strain distribution in the steel layer for the sandwich rolling is better and the rolling force is considerably smaller than the conventional rolling process but the rolling moment is larger in the sandwich rolling. In the sandwich rolling, by increasing the deformation ratio, output layers thickness decrease linearly. Applying the tension forces on the sheet causes the rolling force decreases and affect of the back tension is more than the front tension. By increasing the friction coefficient, maximum pressure point (neutral point) transmitted to the entrance of the roll gap and uniformity of the strain distribution decreases. Increasing the radius of the rolls, increases the rolling pressure and transmits the neutral point to the entrance of the roll gap without much change in the thickness of the layers.