Effect of Laser welding conditions on Austenite/Ferrite Ratio in Duplex Stainless Steel 2507 welds

This paper examines experiments and their results which have led to the achievement of acceptable properties of laser weld runs on a tube of Ø 42 mm, with a wall thickness of 3.5 mm, made of duplex steel type SAF 2507. The experiments have been aimed at achieving acceptable austenite/ferrite proportions by adding additional heat input into the weld region immediately after welding. Furthermore, by varying the additional heat input, it is possible to control the austenite/ferrite ratio. The assessment of the effect of additional heat input on corrosion resistance was not significant, due to the fact that the surface and the root of the welds were heavily oxidized, and since there was spatter in the root region of the weld