Electrochemical Studies of the Effect of Preannealing Temperature and Aging Time on the Degree of Sensitization in 2205 Duplex Stainless Steel

The degree of sensitization (DOS) of an aged 2205 duplex stainless steel preannealed at three solution temperatures was determined using the double loop electrochemical potentiodynamic reactivation method. Solution annealing at 1,250°C prior to 10 min aging at 850°C resulted in a much lower DOS than that of samples preannealed at 1,050°C and at 1,150°C. However, compared to other samples, the increase in DOS of the sample preannealed at 1,250°C was more significant after longer aging at 850°C. A promising correlation between the DOS and the volume fraction of the sigma phase was observed.