The heat resistance of P92 steel decreased with the decreasing dislocation density and precipitated phases coarsening.
The results show that Widmansttten structure needle consists of many blocky subgrains that have higher dislocation density and subgrain boundary is made up of dislocation tangle.
The TEM analysis showed that there are low dislocation density and some low angle boundaries in ultrafine ferrite.
In the past years, the models of flow stress were mainly focused on deformation temperature, deformation speed and deformation degree, but seldom on dislocation density.
