Abstract
In industrial applications, 22 % Cr duplex stainless steel is extensively used to manufacture welded components. However, the steel becomes brittle on thermal exposure at 250–500 °C (known as 475 °C embrittlement). Most existing studies have focused on the solution-treated material, leaving the weld metal largely unexplored. In this study, we characterized a nanoscale structure of 22 % Cr duplex stainless steel weld metal, fabricated using a grade 2209 filler wire and aged at 400 °C for 1,000 h. The presence of Ni-Mn rich solute clusters within BCC-structured ferrite phase was evident, along with spinodal decomposition in the weld metal. A simulation conducted using Thermo-Calc indicated that the clusters were the precursors of the G-phase. The residual stress and the higher Ni content are considered to accelerate the spinodal decomposition of the weld metal. The solute clusters and pronounced spinodal decomposition contributed to an enhanced age hardening of the ferrite in the weld metal.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call