Investigation of the effect of solution annealing temperature on critical pitting temperature of 2205 duplex stainless steel by measuring pit solution chemistry

• The effect of solution annealing temperature on the CPT of 2205 DSS is investigated.
• Solution annealing at 1250 °C causes 8 °C drop in alloy CPT.
• Specimen with lower CPT showed lower diffusing limiting current density.
• Specimen with lower CPT showed higher maximum pit current density.

In this research, the effect of solution annealing temperature on critical pitting temperature of DSS 2205 in 3.5 wt.% NaCl solution and also the pit chemistry is studied using electrochemical methods and mechanistic analyses. Pencil electrode studies revealed that in comparison to samples solution annealed at 1050 °C and 1150 °C, maximum current density in simulated pit solution is increased and limiting current density in presence of salt film is decreased for alloy solution annealed at 1250 °C. Based on these results and microscopic observations, lower CPT of DSS 2205 solution annealed at 1250 °C is explained.