Microstructure and mechanical properties of laser welded S960 high strength steel

Single pass hybrid laser-arc welding of 25 mm thick square groove butt joints

Selective laser melting (SLM) is a successful tool-free powder additive technology. The success of this manufacturing process results from the possibility to create complex shape parts, with intrinsic engineered features and good mechanical properties. Joining SLM steel to similar or dissimilar steel can overcome some limitations of the product design like small dimension, undercut profile, and residual stress concentration. In this way, the range of applications of the SLM process can be broadened. In this paper, the hybrid laser welding of selective laser molten stainless steel was investigated. A high-power fiber laser was coupled to an electric arc and austenitic stainless steel wrought and SLM parts were welded together. The power and speed parameters were investigated. The joints were analyzed in terms of weld bead profile, microstructure, microhardness, and tensile test. The efficiency of the welding process was evaluated through the line energy input versus the weld molten area.

Laser-arc hybrid welding of wrought to selective laser molten stainless steel

The response of the CoCrFeMnNi high-entropy alloy to weld thermal cycles was investigated to determine its applicability as an engineering structural material. Two processes were used: high-energy-...

Microstructures and mechanical properties of a welded CoCrFeMnNi high-entropy alloy

https://www.research.manchester.ac.uk/portal/files/65058553/OLEN_5119_edit_report.pdf

Comparison of microstructure and mechanical properties of ultra-narrow gap laser and gas-metal-arc welded S960 high strength steel

Hybrid fiber laser – Arc welding of thick section high strength low alloy steel

High strength low alloy (HSLA) steel, namely HSLA-65, has shown promise as a replacement for more common high strength shipbuilding steels. However, conventional high heat input welding processes can cause significant distortion, often requiring expensive post-weld reworking. Butt welds in HSLA-65 steel were fabricated using a hybrid fibre laser-gas metal arc welding (GMAW) procedure to investigate the efficacy of distortion mitigation via low heat input joining. Heat input from the laser and arc sources were roughly equal at ~5.2 kW each, and plates were welded in either the laser-leading or arc-leading configuration. In either case, butt welds in ~9 mm thick plates could be made in a single pass at a total heat input of ~0.4 kJ/mm. Welding induced distortion was minimal. Analysis of the microstructure and microhardness of the welds is provided, along with some preliminary results of mechanical and impact testing.

Hybrid Laser-Arc Welding of HSLA-65 Steel Plate: Microstructural and Mechanical Property Evaluation of Butt Welds

Mechanical properties of HSLA-65 hybrid laser arc welds

High strength low alloy (HSLA) grade 80 (HSLA-80) steel with a thickness of 9.1-mm was successfully welded in a single pass using a 5-kW fiber laser combined with an arc welding process. It was found that the maximum gap size in the Y-groove butt joint configuration should remain below 0.2 mm for a 9.1-mm section thickness. Sound butt joints with no welding cracks but some minor microporosity were successfully obtained. However, an underfill defect was frequently observed on the top surface of the weldments. Underfilling could be mitigated through increasing the filler wire addition so as to exceed the groove volume; however, due to significant evaporation and expulsion of the molten pool at the high laser power density, the underfill defect would be difficult to fully eliminate. At slow cooling rates, slight softening in the heat affected zone (HAZ) was present in the mid-thickness region but its elimination is possible at high welding speeds.

Allison E. Nolting

Papers

Hybrid fiber laser – Arc welding of thick section high strength low alloy steel

Hybrid Laser-Arc Welding of HSLA-65 Steel Plate: Microstructural and Mechanical Property Evaluation of Butt Welds

Mechanical properties of HSLA-65 hybrid laser arc welds

Hybrid Fiber Laser – Arc Welding of High Strength Low Alloy Steel