Corrosion Behavior of Cold-Rolled and Solution-Treated Fe36Mn20Ni20Cr16Al5Si3 HEA in Different Acidic Solutions

• Published in: Materials Vol. 15; no. 20; p. 7319
• Main Authors: Mahmoud, Essam R. I., Mohamed, Lamiaa Z., Gepreel, Mohamed A., Ebied, Saad, Abdelfatah, Aliaa
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 19.10.2022; MDPI
• Subjects: acidic media; Cold; Cold rolling; corrosion; Corrosion potential; Corrosion resistance; Corrosion resistant steels; Corrosion tests; Electrochemical analysis; High entropy alloys; High temperature; Intermetallic compounds; Intermetallic phases; Investigations; Low temperature resistance; Mechanical properties; microstructure; Nuclear power plants; Pits; Precipitates; Stainless steel; Stainless steels; Steel alloys; Sulfuric acid
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma15207319

New high entropy alloys with good corrosion resistance in severe environment are receiving increasing attention. This work reports upon the microstructure and the corrosion resistance of the non-equiatomic Fe36Mn20Ni20Cr16Al5Si3 alloy in different acidic solutions. This alloy was designed by thermodynamic calculations using CALPHAD SOFTWARE, fabricated through casting, subjected to cold-rolling and solution-treatment, and compared with SS304 stainless steel. The corrosion test was performed through electrochemical behavior in 0.6 M NaCl and 0.6 M NaCl with 0.5 M H2SO4 and 0.6 M NaCl with 1 M H2SO4 solutions. Experimental results indicate that the alloy is composed of FCC phase as the main constituent besides a small amount of other BCC/B2 phases and other intermetallics. The corrosion test measurements revealed that cold-rolled Fe36Mn20Ni20Cr16Al5Si3 alloy is more resistant to corrosion in 0.6 M NaCl, while it is more susceptible to localized pits in H2SO4 to 0.6 M NaCl. Experimental results indicate that the pits are preferentially occurred in the areas of BCC/B2 phase precipitates. The solution-treated Fe36Mn20Ni20Cr16Al5Si3 HEA has the highest corrosion resistance compared to others with the addition of H2SO4 to 0.6 M NaCl. Surface morphologies of the different conditions were studied, and relevant results were reported.