液态介质中淬火冷却的四阶段理论

一般认为,在液态介质中淬火冷却,工件的散热方式分为三个阶段:蒸汽膜阶段、沸腾阶段和对流阶段.但是,在试验研究中发现了几种三阶段划分不能解释的现象.通过研究这些现象,提出了一个新的阶段:中间阶段.中间阶段位于蒸汽膜阶段与沸腾阶段之间.中间阶段的特点是具有等效厚度的表面上同时存在蒸汽膜冷却区和沸腾冷却区.提供了四阶段划分对应的冷却过程曲线和冷却速度曲线.讨论了中间阶段的特性.

The Four-Stage Differentiation of Heat Removal during Quenching in Liquid quenchant

According to traditional differentiation,there are three cooling stages:vapor stage,boiling stage and convective stage.But in testing,a few unexplained phenomena were observed.By studying those phenomena,a new stage,middle stage,between vapor and boiling stages,was proposed.In middle stage,both vapor area and boiling area are co-exist on the surfaces having the same effective thickness.The corresponding cooling curves and cooling rate curves of four-stage differentiation are provided.The properties of middle stage are discussed.