Influences of preformed blank defects on deformation homogeneity of inconel 718 alloy during conical-section ring rolling process

During conical-section ring rolling process, defects of the preformed blank, such as slope error and concentricity deviation, exert significant influences on deformation homogeneity of the formed ring. According to the geometrical characteristics of conical section ring, influences of slope error and concentricity deviation on deformation homogeneity are explored comprehensively with different rolling ratios based on 3D coupled thermo-mechanical FE model established by FORGE. The results show that during a profile ring rolling process, there is a preparation stage with low and fluctuant friction power. In this preparation stage, local deformation occurs to eliminate the defects of preformed blank without diameters' growth. The defects of preformed blank can affect the deformation homogeneity by determining the length of the preparation stage. Finally, conical-section ring with uniform microstructure was obtained by using the permissible ranges of blank defects proposed in this paper.