Research On Deformation Behavior Of Wide Aluminum Alloy Thick Plate During Angular Rolling

With being more widely applicable,the increasing demand of gauge and property for wide aluminum alloy thick plate can not be satisfied by extant rolling technology.The angular rolling can adjust wide after rolling in a comprehensive range,but there is little research on angular rolling.Through simulation of finite element method and experiments,metal flow during angular rolling process,extend difference distribution in thickness direction,spread,plane shape and section contour of plate are researched.Meanwhile,it is found that deformation of metal in thickness direction of plate is seriously inhomogeneous,which means there is not adequate deformation generated inside the plate and will affect the property of plate seriously.Considering snake rolling has positive effect on improving deformation inside the plate,snake rolling process is researched through finite element method.The Changing laws of equivalent plastic strain,curvature and force condition of roll system under the influence of speed ratio and offset between rolls were obtained.The innovative achievements are as follows:(1)Based on numerical simulation,deformation distribution and law of metal flow during two-pass angular rolling process of wide aluminum alloy thick plate are revealed,and it is found that angular rolling has positive effect on improving crocodile mouth defect.Through establishing three-dimensional finite element model of angular rolling process,motion of plate and distribution of equivalent plastic strain in thickness direction at different location of plate are analyzed.By analyzing metal flow under a large amount of rolling conditions,the changing laws of deformation inside the plate with rotation angles of plate and rolling order are obtained.Then simulation results and the positive effect of angular rolling on improving crocodile mouth defect are validated by experiments.(2)The online predicting models of spread and plane shape are established.According to changing law of metal flow in length and width directions with rotation angles and constant volume law,the predicting model of spread is obtained.Due to inhomogenenity of metal distribution in deformation zone during angular rolling process,the online predicting model of plane shape is established based on calculating deformation of each section of plate.Firstly,changing law of spread and primary width of plate is obtained by a large amount of simulations.Then,the plate is divided into sections evenly and sizes of each section can be calculated.Based on the changing law of spread and primary width of plate,sizes of each section after angular rolling process can be calculated.Finally,by calculating ends coordinary of each section,plane shape can be obtained.(3)Based on influence function method and three-dimension difference method,predicting model of cross section contour of plate during continueous angular rolling process is established.Considering the lack of thickness measuring during rough rolling process,for accurately predicting thickness distribution of plate after angular rolling,a mathematic model of calculating cross section contour in continueous rolling process is proposed.In this model,continueous rolling process is divided in time dimension.Based on sizes calculating of each section,location of plate in deformation zone can be obtained.Then according to rolling forec distribution along contact arc and iterative calculation of whole roll system influence function method and three-dimension metal deformation model,the section contours of plate during angular rolling process can be obtained.Finally,through coordinate transferring and two-dimensional interpolation,the cross section contours of plate are obtained.With applying the spread calculating model and rolling force predicting model to a rough rolling line of wide and thick aluminum alloy plate,problems of spread calculating after angular rolling and rolling force predicting have been solved,the accuracy of setting rolling schedules is highly improved and the demands for flexible setting schedules are met.