Abstract: The dynamic recrystallization and grain growth of discal parts during the double-sided roll forming process are studied by numerical simulation and experimental validation in order to discover the microstructure evolution characteristics in the process. In the study, the disc material is aluminum alloy 6061, and the forming temperature is 350-500 ℃. The conclusion obtained is as follows. The results on grain evolution and its tendency from the test and calculation are in agreement. An important difference of the double-sided roll forming from integral forging of discal parts is that there are no zero strain regions in the rolled part, and that the closer it is to the groove surface, the better is grain refinement. Even rolling with zero increment of compression will cause a nonzero increment in deformation and grain refinement near the rolled groove. For repeated rolling, the contribution of the first rolling to grain refinement is more than that of the subsequent rollings. Higher forming temperature may cause grain growth where dynamic recrystallization and grain growth may appear alternately to cause the increase of final grain size to a certain extent.

Key words: double-sided roll forming, numerical simulation, grain size, grain refinement, grain coarsening, discal part, aluminium alloys