Study On Numerical Simulation Of Radial-axial Rolling Process Of Large Rings

With the rapid development of the wind power generation industry, aeronautics industry and nuclear power industry in China, the demand for high-quality large seamless rings increases continuously. Radial-axial ring rolling is an advanced incremental plastic forming process which is used to reduce the thickness and height, enlarge the diameter and form the profile of the ring by making the ring bite into rolling grooves continuously on ring rolling machine. With the advantage of high material and energy utilization, high product quality, low equipment tonnage and high production efficiency, Radial-axial ring rolling process has become an important production process in producing large seamless rings, which are widely used in areas such as heavy machine, petrochemical engineering, aeronautics and astronautics industry.Radial-axial ring rolling is a complicated forming process with characteristics of nonlinearity, unsteady state and multi-factors coupling interactive effects. At present, radial-axial ring rolling production depends mostly on engineers’experience. There is no complete theory of radial-axial ring rolling to guide practical production. So, further research on the forming mechanism and deformation law of radial-axial ring rolling process needs to be done.Based on the forming characteristics of radial-axial ring rolling, the mechanical and kinematic condition of radial-axial ring rolling were summarized, and the reasonable value ranges of roll size and roll velocity were obtained. By solving the key problem of boundary condition definition, guide rolls motion control, mass scaling definition and mesh generation, a3D FE model of radial-axial ring rolling process was established by ABAQUS/Explicit. By numerical simulation, the distribution and evolution of PEEQ and rolling force were summarized.The constant growth velocity of the ring radius was regarded as the steady forming condition. The reasonable value range of the growth velocity of ring radius was obtained with the combination of mechanical condition of radial-axial ring rolling process. By mathematical reasoning, the feed rate of mandrel and upper axial roll were then designed, and the influences of growth velocity of ring radius on the forming process of radial-axial ring rolling were then researched.Based on the volume constant principle, the blank size was designed by introducing the ratio of height to thickness. By numerical simulations, the influence of main process parameters, such as blank size, driver roll size, mandrel size, axial roll size, rotate speed of driver roll and feed rate of mandrel, on the distribution and evolution rule of PEEQ and rolling force were obtained. The research results provide theoretical guidance for practical production of radial-axial ring rolling.