Critical pitting temperature for Type 254 SMO stainless steel in chloride solutions

摘要: Abstract The variation with time of the open circuit potential high molybdenum containing stainless steel (Type 254 SMO) was measured in 4% sodium chloride solution temperatures range 30–100 °C. plot steady state potentials as function temperature showed an inflection at 50 °C, attributed to decrease oxygen solubility test above 50 °C. Potentiodynamic cycling anodic polarization technique used determine critical pitting (Epit) and protection (Eprot) 4–30% NaCl solutions between 30 100 °C. By plotting two values versus temperature, corresponding (CPT) (CPrT) were determined. Both parameters decreased increasing content. Above CPT, Epit Eprot linearly log[Cl−]. addition bromide ions shifted both towards positive values. In NaCl, increased pH 1–10. combined effect ion concentration on morphology pits examined by scanning electron microscopy (SEM) following potentiodynamic polarization.