Corrosion Behavior of Cold-Rolled and Solution-Treated Fe[sub.36]Mn[sub.20]Ni[sub.20]Cr[sub.16]Al[sub.5]Si[sub.3] HEA in Different Acidic Solutions

• Published in: Materials 2022-10, Vol.15 (20)
• Main Authors: Mahmoud, Essam R. I, Mohamed, Lamiaa Z, Gepreel, Mohamed A, Ebied, Saad, Abdelfatah, Aliaa
• Format: Article
• Language: English
• Subjects: Alloys; Corrosion; Steel
• 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 Fe[sub.36]Mn[sub.20]Ni[sub.20]Cr[sub.16]Al[sub.5]Si[sub.3] 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 H[sub.2]SO[sub.4] and 0.6 M NaCl with 1 M H[sub.2]SO[sub.4] 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 Fe[sub.36]Mn[sub.20]Ni[sub.20]Cr[sub.16]Al[sub.5]Si[sub.3] alloy is more resistant to corrosion in 0.6 M NaCl, while it is more susceptible to localized pits in H[sub.2]SO[sub.4] 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 Fe[sub.36]Mn[sub.20]Ni[sub.20]Cr[sub.16]Al[sub.5]Si[sub.3] HEA has the highest corrosion resistance compared to others with the addition of H[sub.2]SO[sub.4] to 0.6 M NaCl. Surface morphologies of the different conditions were studied, and relevant results were reported.