Laser welding of cold-rolled steel sheets Available to Purchase

The major problems in laser welding of cold-rolled steel sheets are a high reflection of laser beams by sheet surfaces and a strict requirement for sheet fit-up. The laser welding of cold-rolled steel sheets is a heat conduction mode instead of a deep-penetration keyhole welding mode because of thin materials. Experiments showed that reflectivity for cold-rolled steel sheets is in a range of 65-80%. To increase the absorption of laser energy, steel sheets were surface-oxidized, then welded by cw CO₂ laser beams. The reflection with surface oxide films decreases to 30% and the penetration depth was therefore improved. Mechanical properties of weld metals were degraded due to the increase of oxygen concentration. Experiments showed that the using of filler steel powder consisting of manganese and silicon can improve the mechanical properties of weld metals and reduce the strict requirement of fit-up.