Product Code: ICA12_1502

Laser-Arc Hybrid Welding of Thick-Section Mild Steel Plates: Microstructure and Performances of the Beads
Authors:
Geng Li, Wuhan National Laboratory for Optoelectronics, Huazhong Univ. of Science and Technology; Wuhan Peoples Republic of China
Ming Gao, Wuhan National Laboratory for Optoelectronics, Huazhong Univ. of Science and Technology; Wuhan Peoples Republic of China
Chen Zhang, Wuhan National Laboratory for Optoelectronics, Huazhong Univ. of Science and Technology; Wuhan Peoples Republic of China
Xiaoyan Zeng, Wuhan National Laboratory for Optoelectronics, Huazhong Univ. of Science and Technology; Wuhan Peoples Republic of China
Presented at ICALEO 2012

Thick-section steel components are widely used in shipbuilding, bridges and pressure vessels. In this report, fiber laser-CMT(cold metal transfer) arc hybrid welding method was used in joining this kind of steels to improve the production efficiency and reduce the heat input, and 15mm thickness steel plates were welded by two passes with laser power of 6KW. Nice weld seam and good fusion condition is obtained both at the root pass and filling pass, and neither porosity nor crack is discovered in the fusion area acorrding to the X ray test result. Compared to distortion of 5 degrees in fiber laser-pulse arc hybrid welding, little distortion (less than 1 degree) is found in the CMT arc hybrid welding process, and the average grain size of the weld seam organization in the latter is also smaller. Since the weld seam impact toughness reaches more than 85% of the base material, and tensile strength about 20% higher than the base material, the CMT arc hybrid welding process has been proved to be a suitable and effective way in welding of thick-section steels.