Reverse martensitic transformation on the corrosion behavior of a 2304 lean duplex stainless steel

Journal Article · 08 January 2025 · Corrosion Science

DOI: https://doi.org/10.1016/j.corsci.2025.112690 · OSTI ID:2499273

Assumpção, Raphael França ^[1]; Georges, Mariana  ^[2]; Guo, Xiaolei  ^[3]; Farias, Francisco W. Cipriano  ^[4]; Santos, Dagoberto Brandao  ^[5]; Frankel, Gerald S. ^[2]; Sicupira, Dalila Chaves  ^[6]

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1. Universidade Federal de Minas Gerais (Brazil); Ohio State University, Columbus, OH (United States); Colorado School of Mines
2. Ohio State University, Columbus, OH (United States)
3. Colorado School of Mines, Golden, CO (United States)
4. Ohio State University, Columbus, OH (United States); Universidade NOVA de Lisboa, Caparica (Portugal)
5. Universidade Federal de Minas Gerais (Brazil)
6. Universidade Federal de Ouro Preto (Brazil)

This study investigates the influence of the reverse martensitic transformation on the corrosion behavior of 2304 lean duplex stainless steel (LDSS) at low temperatures (400–600°C). The steel underwent cold rolling, followed by isochronal annealing for 0.5 h. Phase transformations and microstructures were analyzed using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Corrosion resistance was evaluated using a syringe cell with cyclic potentiodynamic polarization in 0.6 M NaCl solution and double-loop electrochemical potentiokinetic reactivation in 0.5 M H₂SO₄ + 0.001 M KSCN solution. A bimodal breakdown potential behavior, associated with either pitting or transpassivity, was observed in the as-received (AR) and samples annealed at 400°C. Pitting in the AR sample was associated with Al–Mg–Si–Ca–O inclusions, while pitting on the samples annealed at 400°C was linked to local reduced passive film resistance. Severe cold rolling enhanced the pitting resistance of 2304 LDSS. Selective electrochemical etching revealed preferential corrosion at phase interfaces and within the austenite phase. Additionally, annealing at 500°C to 600°C led to a marked decrease in pitting resistance and increased sensitization. Electron backscatter diffraction analysis of the corroded pits in the annealed specimens indicated that pits tend to nucleate and grow in α'-martensite/austenite regions. Furthermore, the nanostructure formed during low-temperature reversion, characterized by dislocation-cell martensite with high dislocation density and stacking faults, may adversely affect corrosion resistance due to heterogeneities associated with alloying element redistribution.

• Research Organization: Colorado School of Mines, Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE), Nuclear Energy University Program (NEUP)
• Grant/Contract Number: NE0009388
• OSTI ID: 2499273
• Journal Information: Corrosion Science, Journal Name: Corrosion Science Vol. 245; ISSN 0010-938X
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English