Study On Deformation Laws And Forming Process Simulation For Cold Ring Rolling

Cold ring rolling is a kind of continual local plastic forming technology under room temperature. It has the advantage of economy of power, energy and raw material, high productivity, low production cost and high quality. It is a new precise manufacture technology of product many kinds of small seamless rings such as bear race, gear stock and pipe junction.Using ABAQUS/Explicit simulation research and experiment research, from the view of statics and kinematics, it deeply analyzed the basic rules of cold ring rolling deformation, researched the distribution laws of residuary stress, deduced formulas about moving parameters of rollers and constructed design and optimization model for technology parameters. All above researches provided academic and experimental basis for the development of cold ring rolling technology.The elastic-plastic constitutive equation for finite element simulation analysis was construct, which based on mechanical properties of bear steel GCr15 measured in high precision tensile testing machine. According to the structure of D56G90 cold rolling machine, geometrical dimension of rollers, contact condition, loading and adaptive mesh requirement, a 3D elastic-plastic dynamics explicit finite element model of cold ring rolling was built.Through plastic mechanics, plastic forming theory and finite element simulation method, it researched the distribution laws of plastic zone of penetrating process and deduced the plastic penetrating condition based on finite element simulation in cold ring rolling. It researched bite condition and the relationship between friction and bite condition in cold ring rolling. It also researched the influence rule of feed speed, stock dimension and friction on width spread in cold ring rolling. The basic formula of width spread was obtained by numerical fitting. The open cold ring rolling experiments with rectangle section ring was conducted in D56G90 rolling machine, and the results verified above researches.Based on finite element simulation and experiment, the research of residual stress was put forward for the first time. It obtained the variation laws of residual stress in the process of cold rolling deep ball groove section bear race.From the view of kinematics, the moving models of rollers in rectangle section and deep ball groove section ring rolling were built by analytical calculation and finite element simulation. It analyzed the diameter variation rules of two kinds of rings, researched the moving law of guide rollers under special rolling technology condition and worked out complete design method to decide the movement parameter of guide rollers for the first time. According to different feed control models, it worked out the design method of feed speed of idle roller, analyzed the influence of feed speed on deformation and put forward the design thought of using different feed speed in different rolling stages.Through finite element simulation and experiment of cold rolling deep ball groove section bear race, it designed and optimized the roller parameters, movement parameters and stock parameters, obtained the diameter growth rule and circularity variation rule of inner and outer diameter. The close cold ring rolling experiments with deep ball groove section ring was conducted in D56G90 rolling machine, and the results verified the technology design and simulation research.