Laser Welding of Duplex Stainless Steels

The duplex stainless steels have been developed to provide a combination of tensile properties and resistance to pitting and stress corrosion cracking in comparison with the 300¬-series austenitic stainless steels. The optimum properties of duplex stainless steels are achieved when nearly equal proportions of aus¬tenite and ferrite are present in the microstructure. Control of the ferrite/austenite balance in welds is not as straightforward as in the base metals since it depends on different welding parameters as well as type of welding process. This book is concerned with laser beam welding and its effect on size and microstructure of fusion zone then, on mechanical and corrosion properties of welded joints of the widely used 2205 duplex stainless steel plates. Results of laser welding process have been compared with that of tungsten inert gas (TIG) welding process. The results achieved in this investigation disclosed that laser welding parameters including laser power, welding speed, defocusing distance and type of shielding gas combinations play an important role in obtaining laser welded joint with acceptable fusion zone size and weld profile.