Effect of Microstructure on the Pitting Susceptibility of a Martensitic-Ferritic Stainless Steel: A Corrosion-Metallurgical Study
By Carvalho, Ricardo N.; Troconis, Brendy C. Rincon; Pioszak, Greger; Ynciarte, Vinicio; Scully, John R.
Published in Corrosion Science
2022
Abstract
The relationship between microstructure, composition and the localized corrosion resistance of a low carbon Cr-Ni-Mo martensitic-ferritic stainless steel was investigated. Four heat treatments were selected to examine the effect of varying tempered Martensitic-Ferritic microstructures on localized corrosion susceptibility. The pitting potential for each heat treatment was determined in deaerated 192g/L NaCl electrolyte saturated with CO2 (pH: 3.8) at 65 °C. Austenite reversion and other microstructural transformations associated with tempering had a detrimental effect on the pitting potential. The resulting chemical and structural inhomogeneities decreased the pitting potential.