蒸汽膜内气体的流动规律(一)

The Law of the Flow of Gas inside the Vapor Blanket

为解释试验中出现的几个现象,研究了淬火冷却过程中蒸汽膜内气体的流动规律。结果发现,蒸汽膜内气体的流动情况因蒸汽膜所处表面的朝向不同而各不相同。确定了五类基本朝向,研究推测了这些基本朝向的蒸汽膜内气体流动规律。从工件上形成了蒸汽膜开始,到最后一片蒸汽膜消失为止,这些规律一直在试样不同朝向表面之间和各个表面之内形成并且不断增加温度差异。这项规律与先前提出的四阶段理论是相互独立的。它们可能是引起工件超差淬火变形的重要原因。

In order to explain the several phenomena occurred in the experiment, a study is made to find out the law of the flow of gas inside the vapor blanket during quench cooling. The study showed that the flow of gas inside a vapor blanket varied with the facing direction of the surface where the vapor blanket was located. Five basic directions are identified and the laws of the flow of gas inside vapor blanket that face these basic directions are inferred through study. From the formation of the vapor blanket on the work piece to the disappearance of the last vapor blanket, the law acts in the areas that the vapor blankets cover. The act of the law has not only continuously produced and increased the thickness - irrelevant temperature difference inside the surface with the same facing direction, but also brought about an unknown temperature difference among the surfaces facing different directions. The law is independent with the four - stage differentiation theory which was put forward previously. The law and the theory act together, which is probably the main reason for the quenching distortion of work pieces.