Effect of microstructure on the pitting susceptibility of a martensitic-ferritic stainless steel: A corrosion-metallurgical study

The relationship between microstructure, composition and the localized corrosion resistance of a low carbon CrNi-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 192 g/L NaCl electrolyte saturated with CO2 (pH: 3.8) at 65 degrees 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.

Automated summary

The relationship between microstructure, composition, and localized corrosion resistance of a low carbon CrNi-Mo martensitic-ferritic stainless steel was investigated. The study found that heat treatment significantly influenced the localized corrosion susceptibility. Austenite reversion and other structural transformations decreased the pitting potential.