(哈爾濱工業(yè)大學(xué) 現(xiàn)代焊接生產(chǎn)技術(shù)國家重點實驗室，哈爾濱 150001)
摘 要: 選用CuSi3焊絲對鎳基合金/不銹鋼進(jìn)行鎢極惰性氣體(TIG)釬焊實驗，運用OM、SEM和EDS分析接頭微觀組織，通過拉伸實驗和硬度實驗評定接頭的力學(xué)性能。結(jié)果表明：TIG釬焊接頭具有熔焊和釬焊的雙重性質(zhì)，不銹鋼母材局部熔化，生成Fe基熔合區(qū)；在接頭搭接區(qū)及鎳基合金母材與焊縫金屬之間存在界面反應(yīng)層，反應(yīng)層可分為熔化未混合區(qū)、Ni基樹枝晶和晶間Cu基區(qū)；焊縫區(qū)為Cu基體上分布著顆粒狀Fe基固溶體；CuSi3接頭剪切強度達(dá)到195 MPa，接頭斷裂于焊縫與不銹鋼界面處，斷口為微孔聚合機制引起的塑性斷裂；在界面處硬度值發(fā)生突變，Ni基樹枝晶硬度值達(dá)到HV433.3，不銹鋼熔合區(qū)中的Fe基體硬度值達(dá)到HV453.4，近界面處焊縫區(qū)Cu基體硬度值為HV150。
關(guān)鍵字: 鎢極惰性氣體釬焊；界面反應(yīng)層；顯微組織；力學(xué)性能
（State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China）
Abstract:The tungsten inert gas(TIG) brazing of nickel-based alloy and stainless steel using CuSi3 wire was carried out. The microstructures and mechanical properties of the joint were studied using OM, SEM, EDS, instron-testing machine and hardness measurement device. The results show that the joint has dual characteristic and is divided into a welding part on the stainless steel and a brazing part on the nickel-based alloy. The stainless steel fusion zone is made of Fe-based solid solution, the interface reaction layer is made of molten unmixed zone, Ni-based fir-tree crystal microstructure and Cu-based solid solution in the intergranular. The weld is made of α-copper matrix and Fe-based solid solution in the matrix. The shear strength reaches 195 MPa and the shear fracture occurs at the interface between brazing alloy and stainless steel. The microhardness in the Ni-based fir-tree crystal, the Fe-based solid solution of the fusion zone and Cu-based solid solution of the weld near the interface reach HV433.3, HV453.4 and HV150, respectively.
Key words: tungsten inert gas brazing; interface reaction layer; microstructure; mechanical properties
