Joining of 1050/5052 by resistance seam welding and materials evaluation of joints

摘要

Sound 1050/5052 joints can be obtained by resistance seam welding. At an identical welding current, nugget penetration increases with an increasing exhausting pressure. This is due to decreasing pressure acting on the specimen and to increasing Joule heating. An Mg-rich segregation layer is formed in the HAZ near the fusion boundary on the 5052 side. The hardness sharply increases at the fusion boundary of 1050. Despite some scatter of data, the nugget hardness is much the same as the 5052 base metal hardness. This feature implies that 1050 and 5052 inside nuggets are sufficiently well mixed/stirred during welding. The results obtained during tensile shear testing of joints suggest that fracture always occurs near the fusion boundary on the 1050 side and that the tensile strength therefore corresponds to that of 1050. 5052/5052 joints similarly have a tensile strength corresponding to that of 5052. Despite blowholes being formed inside nuggets, they have no effect on the strength of joints.