| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of deformation of a work after welding and a welding defect due to deformation by pouring a coolant around a metal bar/a weld zone and welding while forcedly cooling a work with welding in a coolant. SOLUTION: Welding grooves 4 of a round tube 3 are subjected to friction welding in a longitudinal direction while pouring a coolant 2 around a metal bar 1. A tip part of the metal bar 1 is sharply worked, this sharp part is inserted into a butt welding part and moved in a weld line direction while rotating. For example, a flow rate is 21/min, a rotation number of the metal bar is 1000 rpm, a moving speed is 300 mm/min. This cooling makes a temp. of the neighborhood of a weld zone and the metal bar e.g. <=100 deg.C, by this method, a welding deformation is reduced to <=1/2 as compared to welding without cooling. Further, the metal bar 1 is effectively cooled, to have reduced temp. rise and can weld for a long term without breakage. |
