SHE Peng, SUN Weiguang, MA Chuanping. Research on low temperature toughness of A7N01S-T5 aluminum alloy laser-MIG hybrid welding joints[J]. Eletric Welding Machine2020, 50(4): 111-115.DOI: 10.7512/j.issn.1001-2303.2020.04.20.
The impact toughness and fracture toughness of laser-MIG hybrid welding joints of A7N01S-T5 aluminum alloy for high-speed trains under the temperatures of 20 ℃
0 ℃
-20 ℃
-40 ℃ and -60 ℃ were carried out. The results showed that at the same temperature
the impact toughness and fracture toughness of the heat affected zone(HAZ) was the best
the base metal(BM) was the second
and the weld metal(W) was the worst. With the decrease of temperature
the impact toughness and fracture toughness of the three zones(HAZ
BM and WM) of laser-MIG hybrid welding joints had been improved to a certain extent
but the changes were small.The size of toughness dimples on fracture surface in the heat affected zone and the base metal were larger than that of the weld metal. During the fracture process
large dimples could produce large deformation to resist the crack growth