Analysis of the deformation mechanism of void generation and development around inclusions inside the sheet during sheet rolling processes

The purpose of this paper is to explore the deformation mechanism of void generation and development around inclusions inside sheets during sheet rolling processes. The plastic deformation and flow pattern of sheets with inclusions inside during sheet rolling were simulated by the finite element method. The influences of various rolling conditions, such as the sheet thickness reduction, frictional factors, the ratio of the inclusion diameter to sheet thickness, etc., on the generation and development of voids anticipated to occur in the front and rear of the inclusion are discussed. The critical thickness reductions under which void generation can be avoided are also investigated. Furthermore, experiments on sheet rolling with an inclusion inside the sheet are conducted. The theoretical predictions of the dimensions of the voids after rolling are compared with experimental results and relatively good agreement between them is found.