Predicting polygonal-shaped defects during hot ring rolling using a rigid-viscoplastic finite element method

We applied a rigid-viscoplastic finite element method to investigate polygonal-shaped defects that occur during ring rolling and developed an improved analysis model with relatively fine finite elements near the roll gap to reduce the computational time, along with a scheme to minimize the volume change. We also simulated the formation of a polygonal-shaped defect during hot ring rolling of a ball bearing outer race. The results were in good qualitative agreement with actual experimental phenomena.