球墨铸铁因具有良好的机械性能,因而能代替钢来制作某些工程构件。不过和钢相比,它的主要缺点是焊接性能差,当结构件需用焊接方法裝配或连接时,球铁件往往因焊后容易产生裂纹、或很脆,不能承受工作负荷而不太受欢迎。造成焊后球铁件变脆的主要原因是焊后焊接接头的组织发生了变化,即 Due to its good mechanical properties, ductile iron can be used to make some engineering components instead of steel. However, its main disadvantage over steel is its poor weldability. When structural parts are to be assembled or connected by welding, the ductile iron parts tend to crack easily after welding or are brittle and can not withstand the work load rather than being affected welcome. The main reason for the brittleness of ductile iron after welding is that the structure of the welded joint after welding has changed.