Finite element modelling of effects of roll gap geometry in hot rolling

In hot rolling, rolling load, torque, motor power, and energy are important measurable process outputs that are influenced by the shape and size of the roll gap. The magnitudes of these output variables are dependent on the extent of inhomogeneous deformation during a rolling pass, which is characterised by the redundant shear strain. A previously developed and validated finite element model is used to simulate the deformation behaviour in a rolling pass. The effects of initial slab thickness, reduction, roll diameter, and speed on the rolling load, torque, temperature distribution in the stock, and redundant shear strain have been computed for rolling of Type 316L stainless steel. Two new concepts – the ‘net shear angle’ and the ‘average shear strain’ of a rolling pass have been introduced to quantify the degree of inhomogeneity in deformation. Finally, the results are compared with those of similar rolling theories.