Effect of flame heating pass on microstructure and properties of A6N01 aluminum alloy welded joint

Flame heating combined with water cooling was used to straighten A6N01 aluminum alloy welded joint and effect of flame heating pass on its microstructure and mechanical properties was studied. Results showed that the flame induced the precipitation and growth of the Mg₂Si phase on the Al substrate for the thermal aging A6N01 aluminum alloy welded joints,thus it led the decrease of micro-hardness and tensile strength of the A6N01 aluminum alloy welded joint with the increase of the heating pass. However,the fatigue property of the flame heated joint was improved because the Mg₂Si precipitation hindered the initiation and propagation of the fatigue crack.