supported by the National Natural Science Foundation of China (Nos.51305285 and 51104110);the Basic Research Program of Jiangsu Province (Nos. BK20130315 and BK20130304)
A 4 kW fiber laser was chosen to weld the new hot-rolled nano-scale precipitation-strengthened steel with a thickness of 4.5 mm. The effect of laser power, defocusing distance, and welding speed on the welded joint ap...