Influence of organic/inorganic inhibitors on AISI 304 (1.4301) and AISI 314 (1.4841) steels corrosion kinetics in nitric acid solution

Abstract

This study evaluates the effectiveness of KMnO4, MK3 and 1-butanol inhibitors on corrosion of AISI 314 and AISI 304 stainless steels using linear and potentiodynamic polarization in 0.1 M HNO3. The metrics like corrosion potential (Ecorr), current density (jcorr) and polarization resistance (Rp) influence the inhibitor efficacy. The inhibitors improved electrochemical parameters significantly, indicating strong anti-corrosive properties. 1-Butanol had the strongest effect, enhancing corrosion potential and drastically reducing corrosion current density, demonstrating superior protection. The results indicated that without inhibitors, both steels showed higher corrosion rates and more negative potentials, reflecting their susceptibility to corrosion. The introduction of inhibitors markedly improved these parameters, particularly with 1-butanol, which significantly enhanced the polarization resistance and shifted the corrosion potential towards less negative values. The potentiodynamic results highlighted the dynamic effectiveness of inhibitors, reinforcing their role in mitigating corrosion under varied conditions. The study underscores the importance of selecting the appropriate inhibitors to enhance the durability and longevity of stainless steels in acidic environments, with 1-butanol showing the potential for industrial applications requiring high corrosion resistance. This necessitates comprehensive testing to accurately measure inhibitor capabilities in different conditions.

Keywords

• austenitic stainless steel
• corrosion
• inhibitor
• linear polarization
• potentiodynamic polarization