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Constitutive equations based on isothermal tensile test were applied when traditional researchers performed numerical a- nalysis of high strength hot stamping mechanism.However, dramatic thermal exchange occurs due to large contact between temperature- elevated hot blank and cold die tools, causing it virtually a complicated non-isothermal process.Since the martensitic transformation is strongly dependent on minimum feasible cooling rate, influence of temperature change needed to be considered and new non-isothermal constitutive equation is needed for numerical analysis of desired phase transformation.Using Al-Si coating high strength steel boron steel BR1500HS, non-isothermal uniaxial tensile tests were carried out on a hydraulic servo simulator Gleeble1500.The quenchable boron steel sample had plastic deformation with different cooling rates beginning from 800℃ and ending at 700℃, 650℃, 550℃, 500℃, 450℃ and 400℃ respectively.Optical microscope was used to study microstruc- tural evolution.Different from conventional isothermal deformation, work-hardening types of high temperature rheological curve were ob- tained and new non-isothermal constitutive relationships were regressed to take into account the thermal-mechanical-phase coupling effect.Secondly, numerical modeling of box-shaped parts hot forming was constructed based on the obtained new constitutive equations.The die tools cooling water flow rates varied at 0. 1m/s, 0. 2m/s and 0. 3m/s.Their influences on the microstructure evolution and me- chanical properties are analyzed.Finally, experiments of typical box-shape sheet metal hot stamping are conducted.Deep drawings of these sheets were developed with different cooling rates in order to simulate the actual industrial non-isothermal thermal-mechanical envi- ronment.Through comparison of experimental data and numerical results, the non-isothermal constitutive model of high strength steel has been verified.It provides new support for numerical optimization for quality improvement of hot stamping automotive components.