Mechanical Properties of Single-pass Hybrid Laser Arc Welded 25 mm Thick-walled Structures Made of Fine-grained Structural Steel

High-power laser beam welding for thick section steels – new perspectives using electromagnetic systems

“…The balancing of the hydrostatic pressure with the magnet mounted below the weld root was demonstrated in [12][13][14] for aluminium alloys, [15][16][17] for austenitic stainless steels, and [18,19] for duplex stainless steels with ferromagnetic properties. The first results for ferritic steels were published in [20][21][22][23][24][25], where typical structural steels and pipeline steels were welded. The electromagnetic weld support system could be established for all aforementioned materials.…”

“…On the one hand, those low welding speeds allow a higher heat input into the weld seam, which offers the opportunity to adjust the heat input, the t 8/5 times and thus avoiding extensive martensite formation and guaranteeing good mechanical properties such as hardness and Charpy values. In [24], it could be shown that 25 mm thick constructional steel S355J2 could be successfully welded in a single pass with a welding speed of 0.9 m min −1 and the laser power of 20 kW, resulting in average Charpy values of 60 J @ 0°C in the laser-dominated part, as well as, the average hardness of 258 HV in the fusion zone with peaks up to 318 HV in the HAZ. On the other hand, the heat input could be limited to avoid degradation of the strength in the coarse grain heat-affected zone due to excessive heat input.…”

Influence of shielding gas on filler wire mixing at laser hybrid welding of thick high strength steels

“…Therefore, the terminology of arc-dominated and laser-dominated zone has been established and accepted by many researchers, when reporting on the mechanical properties of laser hybrid welded thick-walled steels, due to different cooling conditions and microstructure in the respective parts [2]. In [3] it was reported that the Charpy impact toughness of a single-pass hybrid laser-arc welded 25 mm thick structural steel plate is decreased up to 60 % in the root part (laser-dominated zone) compared to the top part (arc-dominated zone), where the decrease in cooling time over depth, the resulting microstructure and grain size, together with the inhomogeneous filler wire mixing were the reasons for the inhomogeneous course of the mechanical properties over the seam depth. The uneven filler wire mixing over the entire seam depth is a well-known challenge when laser hybrid welding of thick-walled steels, where elements of the filler wire could be measured up to a depth of 7 mm [4,5].…”

The Effects of HLAW Parameters for One Side T-Joints in 15 mm Thickness Naval Steel

“…Hybrid Laser Arc Welding (HLAW) is an attractive joining method used as a single pass welding technique covering a wide range of thicknesses, with plates of up to 35 mm [1][2][3][4]. It provides good quality joints, minimal thermal distortions and improved productivity in comparison with conventional arc welding.…”

“…Friction stir welding (FSW) seems to relieve some of these problems [16]. In this context, HLAW processes with a laser source seem to be a promising technology to join HSLA steels in shipbuilding [2,21].…”