| 摘要 |
PROBLEM TO BE SOLVED: To suppress both elongation of time required for joining and lowering of the corrosion resistance of a metal-coated steel plate, in a friction stir spot welding method. SOLUTION: A metal-coated second steel plate W2 and non-coated first steel plates W1b, W1a are overlaid in this order to form a workpiece W. A rotary tool 7 is lowered while rotated and then, a to-be-joined part of the workpiece W is held between the rotary tool 7 and a receiving member 8 and pressed in the rotary axis direction from the first steel plate W1a side. Frictional heat is generated by friction between the rotary tool 7 and the surface of the first steel plate W1a. The rotation and pressurization of the rotary tool 7 is continued to cause plastic flow in the first and second steel plates W1a, W1b, W2. Elevated while being rotated, the rotary tool 7 is pulled out of the workpiece W. The workpiece is cooled and hardened to complete its joining. COPYRIGHT: (C)2008,JPO&INPIT |
