Abstract:Aiming to laminated crack defect occurring in the upsetting of heavy disk-shaped forgings, finite element analysis technique was using to establish coupling thermo-mechanical simulation model for upsetting process. By aid of the model, the distributions of equivalent strain, equivalent strain rate and its’ gradients. After analyzing the change law of the different fields, a model of laminated crack defect was setted up based on strain and strain rate gradient, and obtain the morphology distribution of laminated crack at the center of forgings. The numerical simulation result coincides well with the experimental data.