Research On Hot Stamping Technology Of T-Shaped Parts Based On Continuous Simulation Of "Forming + Quenching"

With the rapid development of economy,automobiles have been popularized all over the world,but it also has caused a series of problems,such as frequent traffic accidents and increasingly serious environmental pollution.In order to solve these problems,vehicle lightweight technology based on safety intensity arises at the historical moment,among all kinds of automobile lightweight technology,the hot stamping technology of ultra-high strength steel is undoubtedly a kind of common application.The ultra-high-strength steel hot stamping technology can greatly reduce the weight of the car body while ensuring good body strength and collision resistance,and ultimately achieve the purpose of energy saving and emission reduction.In order to give theoretical guidance for the industrial production of automotive B-pillars,this article simplifies the main forming area of the B-pillars to T-shaped parts,and studies the key process parameters of hot stamping through a combination of simulation and experiment.The specific research content as follows:1)Using the theory of plastic deformation of metal,the phenomenon of metal hardening and various mechanisms of high-temperature softening are analyzed,and the influencing factors of metal plastic deformation are summarized.In the process of hot stamping,the heat transfer mode and heat flow rate between the die and the surrounding environment were discussed,and the effect of different cooling paths on microstructure transformation of UHSS is analyzed.Finally,the type of heat transfer analysis and the algorithm used in hot stamping simulation are determined by comparison,and the basic theory of thermal coupling analysis is introduced.2)Based on the data transfer algorithm in Abaqus,the continuous simulation method of hot stamping "forming + quenching" was established.On this basis,the simulation and experiment of U-shaped parts were carried out,and comparing the variation of the sheet metal temperature field and the thinning rate of the parts,finally the reliability of the simulation method of hot stamping was verified.The results showed that:The simulation is very close to the temperature change and the thinning rate of the workpiece in the experiment.The finite element simulation method in this paper can accurately simulate the hot stamping process of the workpiece and provide effective guidance for the experiment.3)Based on the continuous simulation method of hot stamping "forming +quenching" in Abaqus,the finite element model of hot stamping of t-shaped parts was established.The hot stamping experiment of T-shaped parts was carried out by selecting appropriate parameters,the quality of T-shaped parts obtained by the experiment was tested from the aspects of temperature,microstructure and hardness,compared with the simulation results,the reliability of T-shaped hot stamping finite element model is further verified.Then the influence law of different initial forming temperature,forming speed,holding pressure and holding time on hot stamping forming and quenching stage of T-shaped parts was studied by using control variable method.Based on the changes of temperature field,Mises stress and thinning rate,the reasonable technological parameters of hot stamping for T-shaped parts were determined,which provided technical guidance for practical production.