To provide a welding method that utilizes a friction stir welding (FSW) technique to weld large structures, for example, very large cylindrical tower sections of wind turbines.
The method includes welding at least two workpieces 30, 32 together by metallurgically joining faying surfaces 34 of the workpieces. The workpieces are placed together so that their faying surfaces face each other and a joint region is defined by and between the faying surfaces. The workpieces are then friction stir welded together by forcing a tool 48 into the joint region, rotating the tool about an axis thereof to cause the tool to penetrate the joint region, and causing the tool to travel along the joint region to form a weld joint that metallurgically joins the faying surfaces and produces a welded assembly comprising the workpieces.
Hirokazu Ogura
Toshihisa Kurokawa
Takuto Tanaka