Circular Degree Control Of The Multi-pass Roll Forming Of Super Alloy Ring With Complex Cross Section

The high temperature alloy ring with complex cross section,which has the characteristics of large diameters,thin-wall,small section size and complex shape section.It has been used as a new sealing ring of aerospace precision industry,and it’s the guarantee of the safe operation of equipment.The multi-pass roll forming technology is one of the most effective forming methods to manufacture this type of ring,but if the forming parameters are not well coordinated in the manufacturing process,the ring is easy to produce non-circular defects,which can seriously restricts the improvement of its forming quality and service performance.Therefore,in this paper,the numerical simulation and experimental method are used to study ring’s the non-circular defect in the multi-pass roll forming process of the high temperature alloy,and achieved to control the circular degree of the ring.The research contents and results are as follows:Based on the model developed by the rolling ring,the geometric model and mesh were optimized.The finite element platform based on ABAQUS is developed to satisfy the research needs of the ring finite element model for multi pass roll forming after the key technical problems such as the selection of algorithm,the contact and the loading boundary are solved.The reliability of the model is verified by experiments.Base on the FE model,The influence of the forming parameters on the ring’s circular degree during the multi-pass rolling process was studied systematically.The results show that: With the increase of the speed of the driving roller,the ring’s non-circular degree of each pass decreases first and then increases;With the increase of the feed speed of the driven roller,the ring’s non-circular degree of the latter four passes tends to increase;With the increase of the friction coefficient between the driving roller and the ring,the ring’s non-circular degree of each pass decreases first and then increases.With the increase of the friction coefficient between the driven roller and ring,the ring’s non-circular degree between the first and second pass tend to increase.While the ring’s non-circular degree in the third,fourth and fifth pass decreases first and then increases;With the increase of the friction coefficient between the guide roller and the ring,the circular degree of the ring is in a W shape.Based on the influences of the forming parameters on the rings’ s circular degree,the method of orthogonal simulation test is used and the forming parameters in the multi-pass roll forming process is optimized to improve the defects of the ring’s non-circular degree,the accuracy of this simulation is verified by experiments.The best combination of forming parameters as follows: The speed of the driving roller is 1rad/s in all passes;The feed speed of the driven roller is 0.08mm/s in the first pass,but the latter four passes are all 0.1mm/s;The friction coefficient of each pass between the driven roller and the ring is 0.1,0.2,0.3,0.1 and 0.2 respectively;The friction coefficient of each pass between the driving roller and the ring is 0.1,0.3,0.1,0.2 and 0.1 respectively;The friction coefficient of each pass between the guide roller and the ring is 0.2,0.3,0.2,0.3,and 0.1respectively in the five passes.Finally,the circular degree error of the ring is only 0.436 mm.