热冲压过程中的模内传热现象

Theoretical and experimental research on heat transfer phenomena in hot stamping

为研究热冲压成形过程中的模内传热现象,尤其是模具与板料间换热系数的变化规律,文章提出一个基于界面粗糙度的传热模型。该模型建立了换热系数与接触面粗糙度、硬度、材料导热系数、界面压力等参数之间的关系。同时提出一种非接触式温度采集方法,通过红外成像仪全程记录板料的温度变化,通过逆向分析法推导传热系数的值。结果表明,理论与实验值吻合较好。利用所得结果研究了工艺参数对换热系数的影响规律。

In order to investigate the heat transfer phenomena in hot stamping ,especially the changing rule of heat transfer coeffi-cient between die and blank , a roughness-joint model is presented to describe the relationship between the heat transfer coefficient and those material contact parameters concerned in the hot stamping including roughness , hardness , thermal conductivity coeffi-cient and contact pressure ,etc .Moreover ,a non-contact measurement method based on the thermal infrared imager is developed to acquire the temperature history for the whole process . Heat transfer coefficient is obtained by using the inverse analysis meth-od . The results show that the theoretical values agree with the experimental values well . Furthermore , the influence of the process parameters on the heat transfer coefficient is discussed according to the above results .