Modeling of aging process for pre-rolled Ni-Span C 902 superalloy

The age-hardening curves of hardness measurements obtained for Ni-Span C 902 superalloy under different amounts of cold work, aging temperatures and times showed leveling and pronounced oscillations, indicating instability and reflecting a competition between the effect of sub-structure coarsening and the effect of solute drag and precipitation hardening. An artificial neural network (ANN) was used to model the nonlinear relationship between the parameters of the aging process and the corresponding hardness measurements. The predicted values of the ANN are in accordance with the experimental data. Results showed that the non-deformed and 50 pct cold rolled alloy exhibited a maximum hardness at a tempering parameter of 22 and 21, respectively.