The Numerical Simulation Of Die Forging And Process Optimization For Car Back Plane

The car back plane is an important connection for motor homes,which has high mechanical performance requirement.Due to hot forging process can improve the microstructure of metal blanks,crushing the coarse grain into fine grain and forming forging organized structure,which can improve the physical and mechanical properties of metal,so hot forging process is used to product car back plane.Car back plane has a complex shape,whose rid is thin and high.So the car back plane is classified as high-gluten thin-walled structure.This structure makes forging die bore deep and narrow,difficult forming in the forging process.Duo to the over standard die stress,the die cracks easily while forging.In order to improve die life and blanks filling condition,the optimization for car back plane forging process is needed.In this paper,combining with the actual process parameters,finite element simulation software DEFORM is used to simulate the hot forging process of car back plane,including preforming,pre-forging and final forging.Summarize the flow pattern of forging metal forming process,analyze the stress-strain distribution,temperature distribution,forging load,energy consumption and die stress.Draw the conclusions in view of the above analysis in this paper : the metal blank presses the sidewall of die champer,leading to tensile stress concentration at the bottom of the groove.When this tensile strength exceeds the limit of material,die will be cracked.Die structure design is unreasonable,resulting in insufficient allocation on rib blank,which is the main reason for difficult filling.By analyzing the deficiencies of the original process,combined with design optimizationtheory,a new solution including a new pre-forging die structure and combining preforming and pre-forging is presented.Based on the optimization process,making the maximum stress in the final forging dies,forging energy and forging damage factor as optimization index,material specification,forging temperature,forging speed,and angle of pre-forging die storage silo as optimization factors,the orthogonal experiment with four factors three levels is designed.Through the calculation and result analysis,the paper confirms optimized parameters:the material specification is ?50×205mm,forging temperature is1200?,forging speed is 150mm/s and angle of die storage silo is 30°?The optimized parameters is used to simulate optimization process,and compared with the original process simulation results.The compare results show that: maximum principal stress of final forging die drop by 2360 MPa to 1610 MPa,which less than tensile strength ultimate of die material.Load value drop by 2020 t to 1571 t,while the growth rate is declining.Forging process time reduce from 5.31 s to 2.6s.Forgings' maximum damage factor drop from 0.801 to 0.668.Forgings' deformation work reduce from 136 KJ to93.1KJ.And the research achieve the optimization purpose owing to these results.