Practical Acquisition and Application of Flow Stresses Emphasizing on Prediction Accuracy for Bearing Steel, STB2

A phenomenological model presented by the authors in the previous study, which is a kind of two-region exponential function model, is used to describe flow stress behaviors of bearing steel, STB2. In this model, flow stress is calculated using two separated equations for hardening and softening regions. Peak stress, peak strain, hardening coefficient, steady state stress and softening coefficient are the required parameters for the model. These parameters are then either interpolated using linear regression or used to find some fitted functions of strain rate and temperature to identify the flow stress. The former is called the piecewise bi-linear function model (PLF model) while the latter the closed-form function model (CFF model). It has been shown that the flow stress curves of STB2 steel obtained by these two models are in good agreement with experimental results.