Study On The Influence Of Process Parameters On Cold Roll-Beating Forming Quality

Cold roll-beating forming,as a new type of near-net shape forming technology,is the intermittent hitting and rolling action of workpieces by a high-speed rotating rolling wheel,it forces the local metal material of the workpiece to be plastic flow under the normal temperature.Through the accumulation of the trajectory and the continuous accumulation of deformation,high-performance parts are finally formed.The green roll,energy saving,high efficiency and other advantages exhibited by cold roll forming technology are consistent with the development trend of manufacturing industry,and it is in the leading position in the manufacturing of toothed parts.With the deepening of research on cold roll-beating forming technology,the diversity of influencing factors in the forming process and the multiple coupling between process parameters make accurate control of forming quality become a key issue to be solved in cold roll forming technology.The cold roll-beating forming rack is take as an object of study.The influence of cold roll-beating forming process parameters on forming force,forming precision and surface quality is analyzed by the method of finite element simulation analysis and experimental research.It is found that the interaction between roll rotation speed and feed speed is the main factor affecting cold roll-beating forming process,and the rolling wheel density G is introduced(ratio of rotation speed n to feed speed of of roll wheel).the rolling density on the forming force,the profile precision and the surface quality at different rotational speeds and rolling ways(down-beating,up-beating)is analyzed.The prediction model of the forming force,the forming precision and the surface quality of the cold rolling forming is established,and the optimization of the forming process parameters under the specific conditions is carried out with the genetic algorithm.By reducing the volume of metal deformation and penetration,the formation of bad deformation is effectively suppressed and the forming accuracy is improved.The micro structure deformation of the forming cogging is observed and analyzed,and the hardness is measured.The distribution of work hardening layer is obtained during the forming process.Analysis and test results show that the rolling density has a significant influence on the cogging forming process.With the increase of the rolling density,the forming force is reduced,the profile precision is improved.Under the same rolling density,the forming force increases with the increase of rotational speed,and the forming accuracy increases.the forming accuracy is high but the forming force is high in up-beating.The surface roughness of tooth profile decreases with the increase of rolling density,and the way of up-beating is less than down-beating.The degree of surface hardening is mainly affected by the degree of deformation and dislocation density in each deformation area,and the maximum deformation is at the cogging chamfering,and the hardening degree is the highest.The degree of hardening in the cogging region decreases with the increase of rolling density,and the hardening degree of the parts under up-beating is higher than down-beating.Therefore,in order to improve the forming quality of the rack,the rolling and processing parameters should be selected reasonably.