Evolution mechanism of grain refinement based on dynamic recrystallization in multiaxially forged austenite

Austenite grain refinement based on continuous dynamic recrystallization can be realized through multiaxial forging Fe–32%Ni alloy at 550 °C and 2 × 10− 2 s− 1, which is generally considered not to take place. It not only greatly reinforces the recrystallization theory but also is of great directory significance to the development of new generation iron and steel materials. As a result, the evolution of the continuous dynamic recrystallization during multiaxial forging can be summarized as such a process that deformed bands crossing each other subdivide an austenite grain into several subgrains and these subgrains are gradually angled to new independent grains with their boundaries being transformed into big angle boundaries in subsequent deformation.