Mechanical characterization and microstructure of fiber laser welded TWIP980 steel depending on welding speed and focal distance

The TWIP steels are preferred in the automotive industry due to excellent strength and ductility. In this study, the effect of fiber laser welding parameters has been investigated on the mechanical properties and microstructural points of view twinning-induced plasticity (TWIP) steel. The variation of the mechanical properties depending on fiber laser welding parameters has been determined. The samples were laser-welded with different speeds and focal distances the laser power constant at 4 kW. The stress and elongation decreased when the welding speed increased. The highest stress was obtained at + 1 focal distance. The best energy absorption was seen in b-3 combination (laser power 4 kW, welding speed 130 mm/s, focal distance +1 mm).