BR1500HS高强钢与5CrMnMo模具钢的瞬态接触换热系数

Transient contact heat transfer coefficient between high-strength steel BR1500HS and die steel 5CrMn Mo

利用自制的实验装置,分析热冲压传热过程并将其简化为一维传热,在一定压力和一定的保温时间下测量高强钢和模具的温度变化,基于改进的反传热算法求解在一定界面平均温度和压力以及一定的保温时间下的界面换热系数的变化。研究结果表明:换热系数随着温度和压力的升高而增大且与温度以及压力近似呈幂函数关系,高温时换热系数对压力的敏感性较低温时高。随着保温时间的增加,氧化严重,换热系数减小,且随着压力和保温时间的增加,换热系数逐渐趋于稳定。在一定保温时间下,换热系数只与温度和压力有关,且压力对换热系数的影响较温度对换热系数的影响大,将温度和压力与换热系数很好地拟合在一起,得到换热系数随温度和压力变化的表达式。

Based on self-developed experimental apparatus, the process of heat transfer in hot stamping was analyzed and simplified into one dimension heat transfer and the temperature change of high-strength steel and die steel under certain pressure and holding time was measured. The transient contact heat transfer coefficient was calculated at certain mean interface temperature, pressure and holding time by the improved inverse heat transfer algorithm. The results show that the transfer coefficient increases with the increase of temperature and pressure. The load sensitivity at low temperature is less than that at high temperature. The heat transfer coefficient decreases with the increase of holding time due to oxidation. After certain holding time, the heat transfer coefficient is only related to temperature and pressure, and the influence of pressure on heat transfer coefficient is larger than that of temperature on heat transfer coefficient. The temperature and pressure and heat transfer coefficient are fitted together very well. The expression obtains more accurate heat transfer coefficient which changes with temperature and pressure.