Modeling the hot deformation flow curves of API X65 pipeline steel using the exponential law equation

Different constitutive models are used to model the hot deformation flow curves of different materials. In this research, the hot deformation flow stress of API X65 pipeline steel was modeled using the exponential law equation with strain dependent constants. The results of this model were compared with the results of a model which has recently been developed based on a power function of Zener-Hollomon parameter and a third order polynomial function of strain to power of m (m is a constant)). Root mean square error (RMSE) criterion was used for this purpose. It was found that the he exponential law equation with strain dependent constants has a better performance (lower RMSE) to model the hot deformation flow curves of API X65 pipeline steel. The results can be used further for mathematical simulation of hot deformation processes.