本文重点介绍了水下湿法焊接时焊缝金属中除宏观气孔外还有微气孔存在。文中对微气孔的特征、类型、形成原因及危害进行了初步的探讨,提出了从冶金角度解决微气孔的要领。 This article focuses on the presence of microvoids in addition to the macroscopic pores in the weld metal during underwater wet welding. In this paper, the characteristics, types, forming causes and hazards of micro-pores are preliminarily discussed, and the essentials of solving micro-pores from metallurgical point of view are proposed.