A thermal elastic-plastic finite-element analysis to roll-life prediction on the twin roll strip continuous casting process

The rolling force and roll deformation behavior in the twin-roll-type strip continuous casting process have been computed to estimate the thermal characteristics of a easter roll. To calculate the rolling force, the relationship between the flow stress and strain for a roll material and a casting alloy are assumed as a function of the strain rate and temperature, because the mechanical properties of casting materials depend on temperature. The three-dimensional (3-D) thermal elastic-plastic analysis of a cooling roll has also been carried out, to obtain roll stress and plastic strain distributions, with the commercial finite-element analysis package of ANSYS. Temperature field data for a easter roll, provided by the authors, were used to estimate the roll deformation. Therefore, numerical models considering the thermal and rolling forces have been developed to estimate the roll life. Roll life considering the thermal cycle is calculated using thermal elastic-plastic analysis results. The roll life is proposed in terms of roll revolution in the easter roll models with and without the fine crack failure on the roll surface. To obtain plastic strain distributions of the easter roll, thermomechanical properties of a roll sleeve with a copper alloy are obtained by a uniaxial tensile test fbr variation of temperature. The proposed analysis techniques have improved in easter roll design.