An analysis of the transition between strain dependent and independent softening in austenite

The post-deformation softening behaviour of austenite has been studied for various compositions and deformation conditions. The strain at which the transition from strain dependent to strain independent post-deformation softening behaviour occurs (&epsilon;*) has been found to coincide closely with the strain to the peak stress (&epsilon;p) under certain conditions but not under others. It has been proposed that the relationship between &epsilon;* and &epsilon;p may be described geometrically using the initial grain size and the dynamically recrystallised grain size. <br /

Local Austenite grain size distribution in hot bar rolling of AISI 4135 Steel

In this paper, the local distribution of austenite grain size (AGS) was experimentally determined by conducting single round-oval and square-diamond pass hot bar rolling experiments of AISI4135 steel. The rolling experiments were carried out using the laboratory mill. The local distribution of AGS was also determined numerically. In order to predict AGS distribution, the AGS evolution model was combined with three dimensional non-isothermal finite element analyses by adopting a modified additivity rule. AGS evolution model was experimentally determined from hot torsion test according to Hodgson\u27s model. The predicted results were in a reasonably good agreement with experimental results.<br /