Product Code: ICAL06_1101

Fiber Laser Welding of 780MPa High Strength Steel
Authors:
Zhongjie Liu, Nagoya University; Nagoya Japan
Muneharu Kutsuna, Nagoya University; Nagoya Japan
Guojian Xu, Nagoya University; Nagoya Japan
Presented at ICALEO 2006

A 2kW Ytterbium fiber laser, YLR-2000, was used for welding of 780MPa grade high strength steel-WEL-TEN780RE. The WEL-TEN780RE steel is a kind of heat rolled, fine microstructure low carbon high strength steel used for welded constructions. The effects of defocusing distance, welding speed, shielding gas and its flow rate on cross section bead shape and penetration were studied in continue wave laser beam welding. The effects of frequency and duty cycle on the cross section bead shape and penetration were also studied in pulse fiber laser beam welding. The microstructures of weld metals in different heat input were observed by optical microscopy and scanning electron microscopy (SEM). The hardness of welds was also tested and compared among welds welded at different welding speeds, in other words, in different heat inputs.