Effects of Heat Treatments on the Corrosion Behavior of 13Cr Stainless Steels in Chloride Solutions Containing Carbon Dioxide

Resumo

Various electrochemical measurements were adopted to explore the effects of heat treatments on the corrosion resistance of 13Cr martensitic stainless steels in Cl^– solutions containing carbon dioxide. Phase contents and lattice strains were measured by Matlab image processing and X-ray diffraction, respectively. The compositions of passive film were tested by X-ray photoelectron spectroscopy. The results showed that the enhancement of austenitized temperature can improve the pitting resistance, whereas uniform corrosion resistance can be injured by the formation of retained austenite. The quenched specimen exhibited enhanced passivation stability in long-term immersion tests. Tempering at 280°C as the optimum process can guarantee 13Cr stainless steel a refined microstructure with reasonable internal stress and easy to obtain an intact protective passive film, which can serviced in complicated CO₂ and Cl^– corrosion environment.