| 摘要 |
The purpose of the present invention is to provide an indirect spot welding method with which small circular stone-shaped nuggets can be more stably obtained. In the present invention, in indirect spot welding, an electrode tip section (30) of a welding electrode is characterized by the following: being formed in a two-stage dome shape constituted of a first curved surface (31) comprising the most distal end of the welding electrode and of a radius of curvature r1 (mm) and a second curved surface (32) of a radius of curvature r2 (mm) that are located within the range of a circle of a radius R (mm) centered on this most distal end as seen from the most distal end side; and satisfying formulae (1) to (3). 2√t ≤ R ≤ 6√t ··· (1) 30 ≤ r1 ··· (2) 6 ≤ r2 ≤ 12 ··· (3) Where t is the thickness (mm) of a thinner metal plate. |
