Research On The Cooling Effect Of Hot Stamping Mould With Mixed Discharging Cooling System

Hot stamping is a new complex forming technology, which realizes the combination of the process of forming and cooling quenching. High-strength steel can be processed into automobile body though hot stamping, which realizes the auto weight light and ensures the safety of automobile. The strength of formed parts depends mainly on the degree of it from austenite transformed into martensite in the forming process, and that the transformation degree of martensite relies on formed parts'cooling rate and cooling uniformity. Then hot stamping mould must be equipped with excellent cooling system. Mixed discharging type cooling system which uses cavity-type channels and cooperation of shores for spoiler can effectively achieve uniform and rapid cooling formed parts. Hence, it has important significance that further study the effect of mixed discharging cooling system to accelerating the use of hot stamping mould with mixed discharging type cooling system and promoting the development of automobile manufacturing industry.The mixed discharging type hot stamping mould which gives a comprehensive consideration of the structure strength and rigidity of mould, the computational efficiency and accuracy, is simplified design follow the relevant theories and principles of heat transfer and fluid mechanics, and determined numerical simulation method and turbulence model.The numerical simulation of the cooling effects of mixed discharging type hot stamping mould during packing stage was performed by CFX software, analyzed the influence of different technological conditions for temperature distribution and thermal equilibrium state of formed parts and dies, the cooling effect of the moulds turned to be the best with the holding pressure of 12MPa, the dwell time of 10s and the flow rate of water coolant of 3.5m/s.Some experiments based on BR1500HS are completed in order to study the influence law of hot stamping mould cooling effect in water velocity and dwell time, verify the validity and feasibility of the numerical simulation, find the best process parameters, provide scientific basis and theoretical foundation for the extension of mixed type hot stamping mould and the optimization of its cooling system.