Influence of absorbed nitrogen on microstructure and corrosion resistance of 2205 duplex stainless steel joint processed by fiber laser welding.

After N 2 was added into shielding gas, nitrogen content was increased at upper section and central section of laser weld metal. When shielding gas was pure nitrogen, the microstructure of weld cross-section tended to be homogeneous, its corresponding austenite content was over 40%. The formation of allotriomorphic and penniform austenite was promoted remarkably. The shielding gas of nitrogen was helpful to enhance the corrosion resistance of weldment in 3.5 wt.% sodium chloride (NaCl) solution. [ABSTRACT FROM AUTHOR]