Metal flow law of steel ball forming by skew rolling

Based on the principle of steel ball forming by skew rolling, a finite element model of steel ball forming by skew rolling was established by using software DEFORM-3D. This FEM model was proved to be reliable by contrast with laboratory experiment results. Using the data of FEM results, the metal flow laws in both the radial and axial directions were studied. It is found that metal deformation accumulates in a periodic oscillation way. In the axial direction, deformation at the connecting neck is the most severe, both the radial and axial deformation are larger at the location closer to the connecting neck. In the cross sections, smaller radial compression and larger axial elongation were found at the location closer to the center in the front semi-sphere. Differently, there are smaller axial deformation and radial compression at the location closer to the center in the back semi-sphere.