Research On Numerical Simulation Of Large Ring Rolling And Roundness Tolerance Control

Large ring rolling is a new issue in recent years.With the development of heavy equipment manufacturing industry in China,the demand for large-scale casting and forging is gradually increasing.Large-scale ring rolling is modeled directly through the rolling mill equipment after heating the punched forging to a certain temperature.Roundness error is an important measure of the finished ring rolled products.Now thecontrol of roundness error has no systematic reliable theory,so it is very important to explore the rolling roundness throughthe rolling process parameter change and the roller control.Based on the large ring rolling equipment and process of a heavy machinery plant,a three-dimensional thermos-mechanical coupling model of the tube-shaped ring is established on the MSC.Marc platform to simulate the rolling process of large ring.The thesis analyzes the stress,strain and temperature distribution of the rolling deformation zone,and emphatically study the generation and control of the roundness error.The influence of rolling speed,roll feed rate,roll size and rolling temperature on roundness error was studied by changing the process parameters as well.The thesis analyzes the control methods of the roller force and gets the limit value on the roundness of the ring by finite element simulation.To analyze the influence that the force of the roller on the roundness of the ring by means of finite element simulation.To deduce the ideal position coordinates of the roller based on the expansion speed of the ring and to obtain the force of the roller by finite element simulation.The thesis attempt to put forward the ideal control scheme by comparing with the two control methods to roundness control of the ring.To carry out the ring forging,blank size and tolerance design.In addition to the roundness error caused by rolling eccentricity and vibration,the thesis also analyze the formation mechanism and prevention measures of width,butterfly,taper and uneven wall thickness,which provides a reference for production.Besides,the ring shape measurement equipment is also introduced for practical production and experiment.