Hot deformation behavior and processing workability of ERNiCrMo-3 alloy

Isothermal compression tests for ERNiCrMo-3 alloy specimens were conducted under temperatures of 990-1170 degrees C with strain rates of 0.01-10 s-1. Hot deformation behavior of ERNiCrMo-3 was analyzed based on the obtained flow stress curves. Three constitutive models were developed to anticipate the flow stress: the Arrhenius model compensated by strain, the Arrhenius model optimized by genetic algorithm (GA), and the artificial neuron network (ANN) model. The correlation coefficient (R) and average absolute relative error (AARE) were used to assess the predictive ability for these three models. The R values of the strain-compensated, GA optimized, and ANN models were 91.04, 93.54, and 99.01%, respectively, while the AARE values were 12.30, 8.19, and 2.92%, respectively. Furthermore, the absolute relative error of the ANN model was the most concentrated and mainly around 0. Therefore, the ANN model provides the maximum predictability and accuracy for flow stress. The ANN model was implemented via subroutine USRMTR in DEFORM 2D to simulate the hot compression process of the ERNiCrMo-3 alloy specimens. The numerical results were in good agreement with the experimental results, indicating a high potential for applicability to actual production processes. Finally, hot working characteristic of ERNiCrMo-3 alloy was analyzed by processing map and microstructural investigation. According to the result, the suitable thermal processing domain for ERNiCrMo-3 alloy should be at a temperature range of 1130-1170 degrees C and a strain rate range of 0.03-0.36 s-1.