FRICTION STIR WELDING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a friction stir welding method which suppresses the occurrence of defects. SOLUTION: The end of a face plate and the end of an edge material 520 are butted to each other. A piece 525 overlapping the back surface of the face plate 21 protrudes from the edge material 520. The edge material 520 has a projecting part 523 which protrudes outward. A rotary tool 50 is inserted from the projecting part 523 side and friction stir welding is performed. The rotative direction of the rotary tool 50 is rightward as seen from a large diameter part 51 side. The moving direction of the rotary tool 50 is directed to the back side as seen from the front side of a paper, and in the right side from the axial center of the rotary tool 50, fluidized metal has higher pressure. The overlapped surface between the face plate 21 and the projecting piece 525 exists on the fluidized metal having higher pressure. The projection part 523 is positioned on the left side of the axial center of the rotary tool 50. In such a manner, the production of a continuing oxidized film is suppressed and notch on the overlapped surface is suppressed.