喷雾淬火速率影响因素分析

Analysis on influencing factors of spraying quenching rate

为了探究喷雾淬火速率的影响因素,搭建了可视化试验平台,通过红外热像仪记录高温金属圆盘在高压喷雾冷却过程中的温度变化,并利用简化的微分能量方程分析热量传递过程。对喷射距离和喷射压力对淬火速率的影响进行了定量研究。结果表明,喷射距离越小,圆盘表面温度下降得越快,当喷射距离降低到一定值时,淬火过程可以避过膜态沸腾阶段,从而使冷却速率大大提高。然而,喷射压力对淬火速率的影响并不呈线性规律。本研究首次确定了淬火过程不产生膜态沸腾的喷射距离,为淬火的工业应用提供了重要的理论依据。

To investigate the influencing factors of spraying quenching rate,a visualized platform was established. The temperature changes during the high-pressure quenching process were measured by using infrared camera. Local heat transfer was then calculated from a simplified differential energy balance. The effects of spraying distance and spraying pressure on cooling rate were quantitatively tested. The results show that the temperature declines fast with a short spraying distance. When the spraying distance decreases to a certain value,the vapor film is broken immediately once the quenching process is started. Thus,the spray cooling rate is drastically increased. However,spraying pressure does not exhibit a significant effect on the quenching process. This study first determines the spraying distance for a quenching process without film boiling. Therefore,it will provide an important basis for the industrial application of spray cooling.