Simulation of microstructure evolution during the whole process of radial-axial rolling of TA15 titanium alloy ring

The complete process of the radial-axial rolling of a titanium alloy ring usually includes three operations, namely, the transferring of the heated ring blank from the furnace to the ring rolling mill, the rolling of the heated ring blank, and the cooling of the rolled ring. Each operation can influence strongly the microstructure of the final ring. Therefore, it is important to reveal the characteristics and laws of microstructure evolution of the ring during the whole process of the radial-axial ring rolling for controlling the microstructure and quality of the final ring. Aiming at the whole process of radial-axial rolling of the TA15 titanium alloy ring, the mechanisms and models of microstructure evolution in each operation are clarified first. Then, under ABAQUS environment, a coupled macro-micro and through-process finite element (FE) model of radial-axial ring rolling of TA15 titanium alloy is developed. Extensive simulation results show that: the volume fraction of primary alpha shows an obvious increase but the grain size increases slightly in the transferring operation of the heated ring blank; the grain size of primary α is refined but the volume fraction does not exhibit obvious changes during the rolling operation of the heated ring blank; and both the volume fraction and grain size of primary α increase distinctly in the cooling operation of the rolled ring. ©, 2014, Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica. All right reserved.