Research On Profile Ring Rolling Process

Ring rolling a is a forming process which makes the ring produce local plastic deformation,inner and outer contour forming,wall thickness decreasing and diameter enlarging through continuous biting pass.It has the advantages of saving materials,better mechanical properties,better dimensional accuracy and shorter production cycle.Rolling profile rings is a complex forming process which combines heat transfer,kinematics,dynamics,plastic mechanics and other factors.Rolling profile ring is complex,the contour filling is difficult,and the application range of feed speed is smaller.However,the existing research on the special-shaped ring is not much,and its rolling theory is not yet perfect.In this paper,the forming process of an outer groove ring and an inner step ring is studied by numerical simulation.The diameter and diameter growth rate of the outer groove ring and the inner step ring are deduced.The blanks of the outer groove ring and the inner step ring are designed,and the relevant dies of the outer groove ring and the inner step ring are designed according to the blank size.A semi-closed hot rolling finite element model of outer grooved ring and inner step ring was established.The results show that the forming process of outer grooved rings should be divided into different stages,and different feed speeds should be adopted in different stages.The maximum equivalent plastic strain of semi-closed rolled outer grooved rings is located at the small diameter of the outer surface of the rings and the upper and lower edges of the inner diameter of the rings.After the filling of the outer groove is completed,the rolling expansion force has a process of increasing,and the feed speed should be reduced appropriately.Semi-closed rolling enlargement makes the surface temperature of the ring drop faster,the temperature non-uniformity of the ring decreases,and the temperature at the edge of the inner diameter of the ring is lower.When the inner step ring is rolled by semi-closed ring,the core roll feeding speed is high,which is helpful to increase the average temperature of the ring and to improve the temperature uniformity and strain uniformity of the ring.However,the large feeding speed means that the forming time of the ring is shortened,which makes the average strain of the ring low and the deformation of the ring insufficient.