Mechanical properties of Nd:YAG laser welding of SA508 Gr.4N Ni–Mo–Cr low alloy steel

Pulsed Nd:YAG laser welding of SA508 Gr.4N Ni–Mo–Cr low alloy low steel joint that is using in energy and gas turbine industries were studied. According to the results of metallographic image and the results of microhardness profile, hardness increase was observed in the fusion zone. Also, due to the high heat focus of laser process a very narrow heat affected zone with hardness as weld metal was observed. Results of microstructure and fracture surface were obtained by scanning electron microscopy. Because of the increased strength with fine martensitic microstructure very good connection quality has been created and fusion zone and HAZ unlike other welding methods is not disadvantage of joint. Due to high functionality of modern methods such as laser welding in comparison to traditional methods in reducing defects and problems related to the HAZ, in this study the mechanical properties of this joint is discussed.

Keywords:

Low alloy steel , laser welding , heat affected zone , mechanical properties , microstructure