铸铁等离子束淬火区的特点

通过观察铸铁材料等离子束淬火的组织，并结合等高子束的温度分布，分析了等离子束淬火区的组织转变特点及硬度分布特点。结果表明：铸铁材料等离子束淬火时，淬硬层与基体之间基本没有过渡区，整个淬硬层的组织近乎全部为隐针马氏体，故硬度高，且硬度在整个硬化层没有明显的变化；淬硬层略有凸起，并受到来自未淬火的基体的挤压力，这对于提高硬化带的接触疲劳强度是有利的。

Characteristics of Quenching Zone with Plasma Beam for Cast Iron

The characteristics of structure change and hardness distribution of plasma quenching for casting material was investigated in detail.Through observation of the stucture of cast iron material quenched with plasma beam combining with the temperature distribution of plasma beam.The result shows that there is hardly transitive area between quenching layer and casting matrix by using plasma beam as heating source.The whole quenched layer is almost composed of pure fine martansite,its hardeness is very high and hardly varies in whole hardened layer.The quenching strap is a bit higher than unquenched area,it is stressed by its unquenched neighbor basebody.This is beneficial to enhance wntact fatigue strength of quenched strap.