Investigation and comparison of microstructure and mechanical properties of similar joints of ۳۱۶ stainless steel and ۲۲۰۵ duplex steel by laser welding

Creating a quality joint is one of the current issues in joining materials and materials engineering. Laser welding is one of the newest new processes for joining plates. Stainless Steel ۳۱۶ is an austenitic stainless steel that has received much attention in industries due to its corrosion resistance and high mechanical properties. After identifying the problems of these steels, Duplex-phase steels were introduced that are composed of two phases, austenite and ferrite, equally, one of which is steel ۲۲۰۵. In this study, the laser welding of the same joint of these two steels without filler metal, butt-to-butt, with an input power of ۴۰.۵ Joules, was investigated and compared. By examining the microstructure, it was found that the microstructure resulting from the weld zone of the duplex-phase steel ۲۲۰۵ is composed of the γ-austenite phase and large amounts of the δ-ferrite phase compared to the base metal. By examining the microstructure of the weld zone of the ۳۱۶ stainless steel joint, the weld zone consists of a large amount of austenite and a smaller amount of ferrite than the ۲۲۰۵ duplex-phase steel joint. By examining the tensile strength of the welded joints of both steels under investigation, due to the presence of a higher amount of the hard ferrite phase in the weld zone, the ۲۲۰۵ duplex-phase steel has a higher tensile strength compared to the ۳۱۶ stainless steel. By examining the fracture surface obtained from the weld tensile test, the fracture surface of the ۳۱۶ stainless steel joint was more flexible than the ۲۲۰۵ duplex-phase steel joint.

کلیدواژه ها:

۳۱۶ Stainless Steel ، ۲۲۰۵ Duplex Steel ، laser welding ، microstructure ، mechanical properties.