堆焊铜合金/35CrMnSiA接头的界面结构特征

Characteristic of interface microstructure in joint between copper alloy and 35CrMnSiA steel

采用冷体TIG堆焊方法在钢质基体上堆焊铜合金层,重点分析了其微观组织。通过显微镜(OM)、扫描电镜(SEM)观察了界面、铜合金层及基体的组织形貌特征,分析了焊接工艺对铜合金层中泛铁量的影响。通过能谱(EDXA)研究了铜合金层内和界面的成分变化,发现在焊接过程中发生了基体元素向铜合金层中溶解和某些铜合金层元素向基体扩散,在由CuSi3形成的铜合金层中有Fe2Si生成,在由B30形成的铜合金层中存在树枝晶组织。而且,焊接工艺不当时,因界面处存在低熔共晶进而出现渗透裂纹。

The shell structure consisting of copper alloy surfacing layer and steel substrate was produced by a cool-body tungsten inert gas surfacing method,and microstructure of the shell was mainly investigated.Characteristics of microstructure and morphology of interface,copper alloy layer and steel substrate were observed by using optical microscope,scanning electron microscope.Effects of welding process on the content of Fe within the copper alloy were also analyzed.Energy dispersive X-ray analysis on the composition change of coppr alloy layer and interface shows that solution of some elements from the steel substrate to the copper alloy layer and diffusion of some elements of copper alloy layer to the steel substrate happened during the welding process.There is Fe2Si distributing in the copper alloy layer dispersely when CuSi3 is used as surfacing layer and there is dendritic crystal in the copper alloy layer when surfacing layer is made of B30.Moreover,penetration cracks caused by eutectoid at the interface occurred when the inappropriate welding parameters were used.