| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of weld crack without lowering a welding speed and weld strength by controlling a pulse repeating frequency, pulse lap rate and pulse duty cycle in pulse laser beam welding. SOLUTION: In welding, an irradiating laser beam is controlled under conditions satisfying a laser repeating frequency (f) of <=20Hz, a pulse lap rate R lap of 75% <=R lap <100% and a pulse duty D of 20%<=D<=100%. Further, the pulse lap rate is defined in equation I, wherein, Rn is a nugget axis (mm) in lap welding weld materials 2a, b, S is a feed quantity per laser beam one pulse, V is a welding velocity (mm/sec), (f) is a pulse repeating frequency. Further, when welding under these conditions, generation of weld crack is prevented as well as spatter of weld metal is suppressed, thus, contamination of a laser optical system is eliminated. |
