Multi-Pass Laser and Hybrid Laser-Arc Narrow-Gap Welding of Steel Butt Joints
Multi-pass laser and laser-arc narrow-gap welding make it possible to obtain high-quality butt joints of large-thickness pipe steels with hardness up to 2600...2800 MPa and toughness close to the base metal toughness at a temperature of 20°C. When multi-pass welding methods are used, the subsequent pass makes heat treatment of the previous ones, and reduces the rate of their cooling yet. This allows excluding heat treatment of the joint after welding, which significantly reduces the time and costs for manufacturing large-sized structures.
Dr. Dmitry A. Chinakhov
V. Shelyagin et al., "Multi-Pass Laser and Hybrid Laser-Arc Narrow-Gap Welding of Steel Butt Joints", Materials Science Forum, Vol. 927, pp. 64-71, 2018