(中南大學(xué) 高性能復(fù)雜制造國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用攪拌摩擦焊方法實(shí)現(xiàn)T2紫銅和不銹鋼異種金屬的焊接，得到外觀成形良好、變形小的搭接接頭。通過金相、能譜掃描分析焊接接頭組織。結(jié)果表明：紫銅−不銹鋼搭接接頭后退側(cè)塑性較好的紫銅金屬材料從上往下流動形成層狀流線，在焊縫交界處與塑性較差的不銹鋼金屬材料形成具有模糊界線的區(qū)域組織；焊核區(qū)上表面組織為細(xì)小的等軸晶，紫銅側(cè)組織由于受高溫時間較長，為粗大的等軸晶，鋼側(cè)組織受攪拌針端部作用形成再結(jié)晶晶粒，交界處出現(xiàn)渦流交迭形狀；前進(jìn)側(cè)有兩種組織形貌，即銅基混合條帶和鋼基混合條帶；紫銅−不銹鋼異種材料焊接時在不銹鋼側(cè)存在攪拌頭磨損后脫落的元素成分。
關(guān)鍵字: T2紫銅；不銹鋼；攪拌摩擦焊；搭接接頭；顯微組織
（State Key Laboratory of Complicated Equipment Design and Extreme Manufacturing,
Central South University, Changsha 410083, China）
Abstract:The dissimilar metals of copper (T2) and stainless steel (304) were jointed by friction stir welding (FSW), and the lap joints with good appearance, small deformation were obtained. The microstructure of welded joint was studied by optical microscopy and energy disperse spectroscopy (EDS). The results show that the copper metal with good ductility of the retreating side in the lap joint flows from top to bottom, forms layered streamline. In the interfacial region, regional organizations with vague boundaries are generated with stainless steel metal, which has poor plasticity. On the surface in nugget, the organization shows fine equiaxed grain, the copper side in nugget shows coarse equiaxed grain due to the long high temperature, while the stainless steel side in nugget shows the recrystallization grains originated from the effect of the pin end, and the organization in the juncture shows eddy overlap shape. The organization in advanced side has two morphologies: hybrid striped strap based on steel and hybrid striped strap based on copper. In copper and stainless steel welding process, there are some element worn from the pin tool in the stainless steel base metal.
Key words: T2 copper; stainless steel; friction stir welding; lap joint; microstructure
