Advanced feeding strategy driven by staged growth velocity for groove-section profiled ring rolling

Abstract

Groove-section profiled ring rolling (GSPRR) is a challenging forming process with high flexibility and complex deformation behavior. In the process, feeding strategy is a critical factor affecting the rolling stability and ring quality, thus should be carefully designed. In this work, towards the purpose of establishing a stable rolling process, simultaneously taking the different deformation behaviors during different forming stages into account, an advanced feeding strategy driven by staged growth velocity is proposed for GSPRR process, by which the feed rate of mandrel is adjusted in real time to maintain a constant ring growth velocity vD1 in most of the groove forming stage and a constant ring growth velocity vD2 in most of the pure diameter growth stage. To realize this, mathematical models clarifying the correlation between the ring growth velocity and mandrel feed rate in different forming stages are developed. Besides, the reasonable ranges of growth velocity in different forming stages are determined according to the gripping and penetrating conditions. Integrating the above mathematical correlations into the reliable FE model validated by experiment, the simulation of GSPRR with the feeding strategy driven by staged growth velocity is realized. Through simulations, it is demonstrated that better rolling stability and ring geometry accuracy are obtained under newly proposed feeding strategy compared to the traditional feeding strategy with predefined mandrel feed rate. In addition, it is found that with the increase of vD1 and vD2 in their reasonable ranges, the rolling stability and ring roundness become worse, while the uniformity of strain and temperature distribution become better. Therefore, for a comprehensive consideration, it is recommended to choose the vD1 and vD2 near the median of their reasonable ranges. This work can support the process design and optimization of GSPRR, meanwhile provide a theoretical and technical basis for upgrading industrial rolling mill by integrating the newly proposed feeding strategy into equipment control system.