  A new model has been developed to estimate the flow stress under hot
deformation conditions up to the peak of the stress-strain curves. The model is
constructed on the basis of the general form of sine functions by introducing
an additional exponent. Besides, an equation is derived from the model, which
could be used to predict the critical strain for the onset of dynamic
recrystallization. The model has been examined for a 304 austenitic stainless
steel. The estimated flow stress had an average percentage error of %1.66.
