Evaluation of the roll elastic deformation and thermal expansion effects on the dimensional precision of flat ring rolling products: A numerical investigation

Abstract

Ring rolling is a near-net shape forming process that produces ring products with relatively good dimensional accuracy. Two main factors that lower the precision of the final products are the inability to determine the effects of elasticity and the thermal expansion of rolls during the process. This work focuses on the creation and evaluation of suitable finite element models of a ring rolling process based on available experimental data found in literature. Through these numerical models, the elastic and thermal deformations of the rolls were thoroughly studied and the deformation effect on the produced ring was predicted. A difference of a few millimeters was calculated on the outer and inner diameters of the ring as a result of the two effects, which is far greater than the annotation levels of these products. On the other hand, the effects of the tools’ elasticity and thermal expansion of the ring rolling loads were proven negligible. Based on our analysis it was made clear that slight deformation deviations (thermal and elastic deformations) from the targeted values may cause instabilities to the process if the rolls fail to compensate for these deformations. Material combinations seem to influence the process. Regarding final dimensional deviations it can be concluded that thermo-elastic tool deformations are considerable in case of high product precision requirements.