Determining the Critical Pit Stability Product of Stainless Steels

In this work, a galvanostatic method based on the one-dimensional pit electrode technique was developed to identify the critical pit stability product of 316 L stainless steel (SS). The critical pit stability product of 316 L SS in 0.6 M NaCl at 25 °C was between 0.8 and 0.9 A m −1 , which was confirmed by mass transport modelling and potentiodynamic polarization results in pit-like solutions. The critical concentration of metal cations at the pit base was between 70 and 82% of the saturation concentration. The implications of these findings are discussed in detail.