TWI Industrial Member Report Summary 177/1982
By C J Dawes
Laser welding of butt and T joints in 2, 3 and 4mm thick deep drawing low carbon steels has been examined. The steels include fully-killed, semi-killed and rimming materials. Welds have been made at combinations of laser power and welding speed within the ranges of 1 to 6kW and 1 to 7m/min. The welded joints have been assessed by visual. macrosection and radiographic examinations. The T joints have also been examined for distortion after welding. The results show that both types of joint can be made over a wide range of laser power and welding speed combinations. High welding speeds can be achieved, e.g. butt joints in 3mm thick material were made at a welding speed of 4m/min and a laser power of 6kW. One grade of steel produced cracks in butt welds made at certain welding speed and laser power combinations. The size of the weldability lobes for butt and T joints made in rimming steel was limited by the onset of porosity. No serious distortion of the T joints after welding was observed.