Microstructure and mechanical properties of hybrid LasTIG welds of HSLA steel

摘要

Laser welding accompanied by tungsten inert gas welding was applied for 3 mm thick high strength low alloy S460MC steel butt joining with the aim to study the effect of arc electric current on weld cooling rate and thus weld microstructure and mechanical properties. Preheating realized by the arc decreased microhardness peaks in coarse-grained heat affected zone while strength properties were not degraded. Dissimilar S460MC to DC01 mild steel welds were performed with different positions of tungsten electrode towards the laser beam trajectory to maintain uniform weld profile.