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 th ermal characteristics of a easter roll. To calculate the rolling force , the relationship between the flow stress and strain for a roll mater ial and a casting alloy are assumed as a function of the strain rate a nd temperature, because the mechanical properties of casting materials depend on temperature. The three-dimensional (3-D) thermal elastic-pl astic analysis of a cooling roll has also been carried out, to obtain roll stress and plastic strain distributions, with the commercial fini te-element analysis package of ANSYS. Temperature field data for a eas ter roll, provided by the authors, were used to estimate the roll defo rmation. Therefore, numerical models considering the thermal and rolli ng forces have been developed to estimate the roll life. Roll life con sidering the thermal cycle is calculated using thermal elastic-plastic analysis results. The roll life is proposed in terms of roll revoluti on in the easter roll models with and without the fine crack failure o n the roll surface. To obtain plastic strain distributions of the east er roll, thermomechanical properties of a roll sleeve with a copper al loy are obtained by a uniaxial tensile test fbr variation of temperatu re. The proposed analysis techniques have improved in easter roll desi gn.