A New Rolling Model for Three-Roll Rolling Mills

Abstract

During the last 90 years, a lot of works have been published about rolling theories for the two-roll rolling process (2RP). In the last decades, the three-roll process (3RP) has become a significant technique in the production of wire rod and bars, as it allows to cover a wide range of finished dimensions with one pass design, or to realize very close tolerances, depending on the pass design method used (free size rolling or high precision rolling). Horihata and Motomura [2] made use of the upper bound theorem to construct a method for spread calculation, but up to now, a straightforward mathematical method for calculation of stress distribution, roll forces, torques and forward slip is still missing. The present paper aims at a transfer of the slab method, which is well-known and established for the 2RP, to the 3RP. After the rolling theory for flat passes is introduced, Lendl’s equivalent pass method is transferred to the 3RP, which allows the calculation of section passes. Computational results show, that roll forces, torques and forward slips can be calculated under inclusion of elastic stand feedback and interstand tensions. Therefore the model can be used for roll speed set-up to minimize interstand tensions, which is of great importance for the rolling industry.