Description
For applications of the chemical, gas and oil industry duplex stainless steels are mostly used due to good corrosion resistance and mechanical properties. These performances are archived by a microstructure of ferrite and at least of 30 % austenite. To ensure the properties, the energy per unit length EL of the welding process must be suitable adjusted for duplex stainless steels. In this context, one-layer laser beam-submerged arc hybrid welding processes were developed for butt joints of duplex stainless steel S31803 (t = 16 mm). In this study, the metallurgical and mechanical properties of weld seams are investigated by metallographic analysis, tensile test and Charpy impact test depending on EL. All weld seams meet the requirement of at least of 30 % austenite, but the weld seams achieve the highest impact energy of 131 kJ by using a lower EL of 1740 kJ/min. This is caused by finer microstructure.