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Indexed by:期刊论文

Date of Publication:2018-01-01

Journal:JOURNAL OF MANUFACTURING PROCESSES

Included Journals:SCIE、EI

Volume:31

Page Number:131-138

ISSN No.:1526-6125

Key Words:Arc welding; Laser; Mg/steel dissimilar metal; Filler metal; Butt joint

Abstract:The most common welding method for Mg/steel dissimilar metals is melt-brazing with lap joints; however, the butt fusion welding of Mg/steel joint remains a challenging task. 1.6 mm AZ31 B Mg alloy was joined with 1.0 mm Q235 steel by using laser-gas tungsten arc welding (GTAW) hybrid butt welding with AZ61 filler metal. The influence of welding heat input on the morphology, interface bonding, mechanical properties and fracture modes of welded joints was systematically analyzed.
   Results: show that laser-GTAW hybrid welding with filling wire can be used to combine high-performance joints and Mg/steel dissimilar metals during butt assembly. The maximum average tensile fracture load of the joints can reach up to 3265 N (the load equal to that of steel base metal). The tensile load of the joints decreases with the decrease in heat input. A reaction layer is formed on the welding interface enriched with Al and Mn elements. The morphology of Mg/steel joint and the thickness of interface transition layer are the key factors affecting the properties and fracture mechanism of the welded joint. With the decrease in heat input, the Mg/steel butt joints had three fracture modes, including the fracture on the base metal of steel, Mg weld seam, and Mg/steel interface. (C) 2017 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.