Six different mathematical models to predict the hot deformation behavior of C71500 cupronickel alloy

Abstract:

Base on the Gleeble-3500 thermo mechanical simulator, the real stress-strain data of C71500 cupronickel alloy in isothermal compression test were obtained in the temperature range (1073-1273k) and strain rate range (0.01-10s-1). Johnson-Cook, modified Johnson-Cook, modified Zerilli-Armstrong, Arrhenius-type, Fields-Backofen-Zhang and Zhou-Guan models were used to regress the constitutive equation of high temperature flow stress. The applicability of the six models were evaluated by comparing the accuracy, correlation coefficient (R), root mean square error (RMSE), average absolute relative error (AARE), the number of uncertaintyl and the time consuming for calculation of these parameters. According to the fitting results of parameters and time consumption, the Zhou-Guan model is the best for predicting the deformation resistance of C71500 alloy at different strain rates and temperatures. The results provide a theoretical basis for the capability selection and verification of C71500 alloy and other similar copper alloys which are not easily deformed by cold working.

Key words:cupronickel; mathematical model; hot deformation; flow stress