서강대학교

초록/요약

The research work proposed in this paper aims to detail a useful algorithm for predicting the geometric growth of a flat ring in a radial-axial ring rolling process when different velocities approaches are utilized during the expansion phase of the ring. Based on the experimental results, the analysis of the slippage between ring and roll during actual ring rolling production is also analyzed and an interpretation of this phenomenon is also proposed. The shape prediction algorithm proposed in this paper has been subjected to a two - step verification process. In the first step, experimental results have been compared with the analytical prediction for the case of a ring made of Al6061 forged, by means of ring rolling process, at the initial temperature of 150˚C. The comparison between analytical and experimental, for the outer diameter of the ring, have proved the reliability of the proposed approach and a maximum error equal to 1.7% has been computed. In the second validation phase, the numerical results of different rings made of 42CrMo4, Ti6Al4V, and Al6061, with an outer diameter ranging from 800 mm to 2000 mm, manufactured considering bilinear and trilinear mandrel feeding speeds, have been compared with analytical prediction computed by utilizing the developed algorithm. In this second comparison, the results have shown a maximum error equal to 6.82% proving, once again, the reliability of the proposed algorithm also for the case of different materials. Thus, the proposed algorithm is reliable for industrial applications regardless the size of the ring, the material of which the ring is made of as well as the number of mandrel of feeding speeds utilized during the expansion phase of the process.