| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser welding method which can prevent the occurrence of porosity in performing multi-layer welding.SOLUTION: A first layer is welded by means of a keyhole laser welding with a light condensing diameter of a laser beam LB which is controlled lower than a threshold between a value corresponding to the keyhole laser welding and a value corresponding to heat conduction laser welding, and then a second layer and subsequent layers are welded by means of the heat conduction laser welding with a light condensing diameter of the laser beam LB which is controlled higher than the threshold. |
