After being rolled at forging temperature most rings are heat treated (i.e. normalized, quenched and tempered). Due to this processing some rings, especially those with a large outer diameter to wall thickness ratio, distort and become oval, i.e. out of tolerance. This distortion is not the only problem resulting from this phenomenon. Even if the finished rings meet dimensional tolerances and are shipped to the final costumer, residual stresses resulting from heat treatment may become a problem during subsequent machining causing additional deformation and distortion.
Understanding this problem is a challenging task considering the three triggering mechanisms (thermal, metallurgical and mechanical) that affect the ring during heat treatment causing the undesired results. This study covers the prediction of geometric distortion and residual stresses in rolled and heat treated rings. Due to its versatility, accuracy and efficiency, the Finite Element Model technique was used to simulate the heat treatment process of a large ring, resulting in the prediction of geometric distortion and residual stress distribution in the ring under certain conditions for heat treatment.