Feeding interval design considering multiconstraints in flat ring rolling process

Abstract

This paper aims to develop a feeding strategy for flat ring rolling process in a systematic way. Firstly, an accurate prediction for ring diameter expansion is quite essential for ring rolling, so a new mathematical model for predicting the diameter expansion of the flat ring in radial-axial rolling process has been proposed, in which the variation of ring cross section and the particularity in initial rolling phase are taken into consideration. Based on the new model, the feeding constraint due to the ring outer diameter expansion can be obtained accurately. Secondly, the gripping and penetration conditions are included in the feeding schedule design. For the gripping condition, the uneven contact pressure distribution of the working rolls on the deformed ring is calculated according to the practical condition, which is different from the traditional assumption as uniform distribution and avoids oversimplification. The rolling force capability constraint is also included in the feeding interval design as the third factor considered. For a hot rolling process, the initial rolling temperature and finish rolling temperature have great influence on the ring performance, microstructure, and forming error formation. Therefore, the rolling temperature constraint is also being considered. The condition for forming error free such as fishtail free is considered as the fifth factor in the feeding interval design. Based on the feeding interval established, the quantitative design of a flat ring rolling process is realized both in simulation and in practical production, which proves the validity of the feeding interval design.