【摘要】 对2 mm厚的LF2铝合金和Q235钢平板试件进行了加入中间过渡层金属Cu的电子束对接焊接试验,利用光学金相、扫描电镜及能谱分析等方法研究了接头各区域的组织结构和成分分布。结果表明,接头可分为三个焊缝组织区域,其中靠近钢侧的焊缝区主要为Fe基固溶体,并含有少量金属间化合物;靠近铝侧的焊缝区为含有Fe-Al系及Al-Cu系金属间化合物的Al基固溶体;焊缝中部区为呈层带状分布的多种Fe-Al以及Al-Cu脆性金属间化合物混合区。分析认为虽然引入了铜过渡层,但在焊缝中依然有较多金属间化合物生成,特别是焊缝中部区域上,呈连续层带状分布的多种脆性金属间化合物的产生是影响接头强度的主要因素。在对接头组织结构分析的基础上,建立了描述LF2/Q235异种金属电子束对接接头形成过程的物理模型。更多还原

【Abstract】 Butt welding of dissimilar metal between Al alloy LF2 and carbon steel Q235 with the middle transition metal of Cu was carried out by electron beam welding.The microstructures,elements distribution in the joint were investigated by means of optical micrography,SEM and EDX.The result showed that the macrostructure in the joint can be divided into three zone. One is Fe based solid solution with a small amount of intermetallic compounds at the weld zone near to steel side.One is Al based solid solution with a definite store of Fe-Al and Al-Cu intermetallic compounds at the weld zone near to aluminium alloy.The other is mixed intermetallic compounds zone which consists of the several kinds of Fe-Al and Al-Cu intermetallic compounds at the middle weld,and its distribution is layered and banded.The analysis indicated that more intermetallic compounds were made in the weld although the transition metal Cu was used, particularly the multiple bedded and zonal intermetallic compounds formed and distributed in the middle weld are the main factor to influence the strength of the joint.Based on the analysis on microstructure of the joint,the physical model was founded to describe the forming process of dissimilar metal joint between Al alloy LF2 and carbon steel Q235 with transition metal Cu by EWB.更多还原