Quenching Of High Temperature Clinching InHigh Strength Steel

As high-strength steel and aluminum alloy are widely used as lightweight materials for vehicles,how to realize the connection of steel-aluminum dissimilar materials has become the research focus.In this paper,high-temperature clinching process is used to clinching of high-strength steel and normal-temperature aluminum alloy under high temperature condition,which overcomes the limitation of traditional technology in dissimilar metal connection and realizes the effective connection of high-strength steel and aluminum alloy.In this paper,the finite element modeling and experimental methods are combined to study the clinching and quenching phase transformation process of high temperature riveting process.Firstly,the thermal parameters of steel and aluminum were measured by material experiment.Based on the experimental thermal parameters and actual process requirements,high temperature clinching and quenching die were designed.The high temperature clinching and quenching finite element model was established.The heat transfer experiment of high temperature steel plate and room temperature aluminum alloy was carried out.Compared with the finite element simulation temperature curve,it is verified that the finite element model can effectively simulate the heat transfer in the high temperature clinching process.Based on the effective finite element model,the sensitivity of cooling parameters and the effect of cooling method on the temperature field of high-strength steel sheets were studied.The high-strength steel phase change subroutine was established by using the secondary development function of abaqus.The accuracy of the phase change subroutine in the phase change operation was verified by comparing the model operation results with the phase change experimental data.The high temperature clinching experiment was carried out to obtain effective clinching.The phase change type and phase content data of the joint material were obtained by X-ray diffractionscanning and compared with the finite element simulation results.It was further verified that the high temperature clinching phase transformation model can effectively simulate the phase transition of the high temperature clinching quenching process.Based on the effective high temperature clinching phase transformation model,the effects of different cooling methods on the phase change content were further investigated,and the phase transition principle was analyzed based on the finite element phase transition history data.According to the results of the phase change model,the mechanical curves of22MnB5 high-strength steel were constructed on the basis of two equal strain models.The uniaxial tensile test was carried out on 22MnB5 high-strength steel under different heat treatment processes.According to the experimental results,two equal strain models were applied.The correction and fitting were carried out to describe the mechanical properties under different phase content ratios,which provided a reference for the mechanical properties of the joint materials with different phase content ratios.On the basis of the second,the quenching parameters such as coolant temperature and convection heat transfer coefficient were investigated.According to the results of the investigation,different quenching schemes were designed according to the results of the cooling medium,cooling temperature and coolant flow rate.The phase transformation content of the joint was controlled,and the average content of each phase was and distribution uniformity was analyzed and compared.