Study On The Influence Of Radial Reduction Ratio And Feed Ratio On Radial Forging Quality

The radial forging is a kind of effective metal plastic forming technology, which has been used in industrial production widely. It shows that the radial forging can increase the metal plasticity, reduce friction, improve surface quality and dimensional accuracy significantly. At present, the theory of radial forging has not been established and the study on radial forging is still in the test phase. As an important volume forming technology,it is difficult to guarantee the quality, prone to exercise tight, face appeared pits and double drum defect, back, ridged, internal crack, shrinkage cavity and a series of problems during the forging. Aimed at these problems, the basic law and the practical application has been studied. The main content is summarized as below:An axisymmetric finite element model to simulate the radial forging process was established and verified, dimensionless parameters were adopted, the stress and strain distribution, forging force and the pit defects were analyzed. Based on the criteria of uniform equivalent strain distribution, no concave profile in end surface, presenting compressive stress during forging and no residual tensile stress after forging at the center,reasonable combination of the radial reduction ratio and feed ratio was determined. Finally an example of selecting radial forging process parameters, considering forgings quality, productivity and capacity of the forging equipment, was presented. The summarized rules to select process parameters provide the basis for radial forging process design and optimization.A 3D finite element model to simulate the radial forging process was established and verified, dimensionless parameters were adopted, the stress and strain distribution, forging force and the pit defects were analyzed. The hole was added in 3D finite element model and the hole evolution was studied during radial forging. To ensure the quality of forgings, and get good mechanical properties as well as to extend the life of forgings, the parameters should be selected legitimately.At last, the experiment has been done to verify the simulation, such as the effect on strain,the feed ratio on end defects、the void evolution. And the error has been analyzed.