환상압연공정에서 측면유동에 의한 어미현상(Fishtailing)의 예측에 관한 연구

Abstract

The open-pass ring rolling of rectangular cross-section is simulated by the three-dimensional rigid-plastic finite element method to predict fishtailing. Because the ring rolling process is incremental and the deformation region is restricted to the vicinity of the roll gap, only a ring segment spanning the roll gap is analyzed in order to save computation time. The strain rate distribution, roll separating force, driven roll torque, normal pressure distribution and the cross-sectional configuration of the deformed ring are calculated. Comparisons between computation and experiment show good agreement in roll separating force, driven roll torque and especially in the cross-sectional configuration of the deformed ring, i.e. the effect of fishtailing.