| 摘要 |
　The purpose of the present invention is to provide a spot-welded joint and a spot welding method whereby the fracture toughness of spot-welded metal is increased and the strength of the spot-welded joint is improved. The present invention is a spot welding method including a welded part formation step for forming a welded part by current conduction, and a solidifying step for conducting electric current lower than the electric current conducted in the welded part formation step to cause the welded part to solidify, the solidifying step following the welded part formation step. In the solidifying step, electromagnetic vibration is applied to the welded part, and the frequency fV of the electromagnetic vibration, the solidifying rate νS when the welded part solidifies, and the arm spacing λD of dendrites (31a) when the welded part solidifies satisfy the relationship 0.2= νS/(λD･fV)= 4.0. |
