Comparative Study of Bypass-Current MIG Welded–Brazed Aluminum/Galvanized Steel and Aluminum/Stainle

• 作 者: Yu-Gang Miao Guang-Yu Chen Peng Zhang Duan-Feng Han
• 机 构: National Key Laboratory of Science and Technology on Underwater Vehicle, Harbin Engineering Universi
• 出 处: Acta Metallurgica Sinica(English Letters)
• 发表日期: 2017年08期
• 关键词: stainless assembling microhardness bypass Bypass joints intermetallic welding in

A bypass-current metal inert-gas welding–brazing technology has been developed to join aluminum/galvanized steel and aluminum/stainless steel. Microstructure, intermetallic compounds and hardness distribution of the joints were studied by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction analysis and microhardness tests. Comparative study on both types of joints was carried out. During aluminum to galvanized steel assembling, finer seam was obtained under a more stable process. A uniform interfacial reaction layer with a thickness of 2–4 μm was formed. During aluminum to stainless steel assembling, an uneven interfacial reaction layer with a thickness of 5–45 μm was formed. Intermetallic compounds at the interface of aluminum/galvanized steel were identified as Fe–Al–Si–Zn complex phases, while Fe–Al–Cr–Ni complex phases were found at the aluminum/stainless steel interface.Microhardness of interfacial layer increases rapidly within reaction layer due to possible brittle intermetallic compounds.

A bypass-current metal inert-gas welding-brazing technology has been to join aluminum / galvanized steel and aluminum / stainless steel. Microstructure, intermetallic compounds and hardness distribution of the joints were studied by optical microscopy, scanning electron microscopy, energy-dispersive Comparative study on both types of joints was carried out. During aluminum to galvanized steel assembling, finer seam was obtained under a more stable process. A uniform interfacial reaction layer with a thickness of 2- 4 μm was formed. During aluminum to stainless steel assembling, an uneven interfacial reaction layer with a thickness of 5-45 μm was formed. Intermetallic compounds at the interface of aluminum / galvanized steel were identified as Fe-Al-Si-Zn complex phases , while while Fe-Al-Cr-Ni complex phases were found at the aluminum / stainless steel interface. Microhardness of interfacial layer increases rapidly within reaction layer due to possible brittle intermetallic compounds.