熔化焊接头“不均匀混合区”的形貌特征研究

Study of the Appearence Characterstics in the Heterogenous Mixture Zone of Fusion Welded Joint

通过时大量熔化焊接头的金相观察，研究了熔化焊接头焊缝底部附近“不均匀混合区”的形貌特征。归纳金相观察结果，发现不均匀混合区由小岛、半岛、后续熔化滞留层、扩散过渡层四种形貌构成。文中关于熔化焊接头“不均匀混合区”的形貌划分方法，能很好地解释熔化焊接头中焊缝底部附近的成分、组织、性能不均匀性的形成原因，有助于正确理解熔化焊接头的特征区域构成。

The appearence characteristics of the heterogenous mixture zone near the bottom of weld metal in the fusion welded joint are studied through metallographic observations of many fusion welded joints.It was found out that the heterogenous mixture zone is composed of little island.Peninsula.follow-up melted stagnant layer and diffusion transition layer.Their formation processes are analysed in detail.This appearence classification method of heterogeneous mixture zone can explain satisfactorily the formation reason of the inhomogeneity of composition.structure and property near the bottom of weld metal in fusion welded joint,and is conducive to understand correctly the formation of characteristic zone of fusion welded joint.