Integrating Physical and Numerical Simulation Techniques to Design the Hot Forging Process of Stainless Steel Turbine Blades

he paper presents a joint application of finite-element-based numerical simulation and real-material-based physical simulation techniques for design and optimisation of the hot forging operations to manufacture high strength stainless steel turbine blades. 2D simulations of the forging steps carried out using a suitably calibrated finite element model are combined with systematic analysis of microstructure evolution during forging experiments, with particular care to formation of the brittle δ-ferrite phase at high temperatures. A correlation is established between microstructure and thermal and mechanical parameters characterising forging operations. On the bases of numerical and experimental results, the actual forging process is re-designed, reducing the total number of forging steps. Industrial trials, conducted with the optimised process parameters, demonstrate the effectiveness of the developed procedure.