The effects of welding current on microstructure and mechanical properties of the welded joint of 6008-T66 aluminum alloy/H220 YD steel were investigated

and mechanism of the fracture behavior of dissimilar metal welded joints was enpound. The results show that with the welding current increasing from 18 k A to 22 k A

the nugget diameter and indentation rate exhibit a rapidly increasing trend

however

with the welding current more than 22 k A

the nugget diameter remains stable or increased slightly

while the indentation ratio is increased gradually. The thickness of intermetallic layer in the interface of aluminum/steel welded joint is increased with the increase of welding current

and the thickness reaches 7. 1 μm when the welding current is 25 k A. With the increase of welding current

the tensile shearing force of 6008-T66 aluminum alloy/H220 YD welded joint is increased firstly and then decreased

and the maximum value can be obtained when the welding current is 22 k A. When the welding current is 22 k A

the tensile shear specimen is broken at the nugget with the button breaking mode

and the welding current is too high or too low

the tensile shear specimen is cracked at the interface.