Cyclic Corrosion Behavior and Protection Mechanism of Oxygen-Containing Bilayer NiCoCr Coatings in Alternating Salt Spray and High Temperature Environment
MATERIALS CHINA[ISSN:1674-3962/CN:61-1473/TG]
- Issue:
- 2026年08
- Page:
- 50-59
- Research Field:
- Publishing date:
Info
- Title:
- Cyclic Corrosion Behavior and Protection Mechanism of Oxygen-Containing Bilayer NiCoCr Coatings in Alternating Salt Spray and High Temperature Environment
- Author(s):
- YANG Yue; YANG Shasha; CHEN Yongjun; LI Gangfei; XIE Zhiwen; WANG Tuo; CHEN Minghui; WANG Fuhui
- 1.State Key Laboratory of Digital Steel， Northeastern University， Shenyang 110819， China
2.School of Materials Science and Engineering， Northeastern University， Shenyang 110819， China
et al.
- Keywords:
- NiCoCr coating; salt spray-high temperature alternating corrosion; cyclic corrosion; Cr2O3 protective film; bilayer nanocrystalline coating
- CLC:
- PACS:
- -
- DOI:
- -
- DocumentCode:
- Abstract:
- To elucidate the cyclic corrosion behavior and protection mechanism of NiCoCr coatings with different microstructures in alternating salt spray and high-temperature environments, a systematic study was conducted on 316L stainless steel substrate and three NiCoCr coatings (AIP, MS, and MSO5) using a neutral salt spray (24 h)-high temperature oxidation (800 °C, 5 h) alternating cyclic test. Combined with mass change measurements, X-ray diffraction,scanning electron microscopy, energy dispersive spectroscopy, and electrochemical impedance spectroscopy, the formation and evolution characteristics of corrosion product films on different materials were analyzed. The results indicate that the long-term corrosion resistance ranking of the four materials in the salt spray-high temperature alternating environment is MSO5>MS>AIP>316L. The 316L substrate and AIP coating entered the mass loss stage after 90 h and 180 h, respectively, while the MS and MSO5 coatings maintained positive mass gain throughout 300 h, with the MSO5 coating exhibiting the smallest and most stable mass gain. After 150 h, the AIP coating formed a multi-layered loose oxide film, the MS coating formed a double-layered oxide film with localized defects, whereas the MSO5 coating developed a continuous and dense protective film predominantly composed of Cr2O3.After 300 h, both AIP and MS coatings exhibited significant internal oxidation with corrosion depths reaching 40.6 μm and 17.7 μm, respectively, while no obvious internal oxidation was observed in the MSO5 coating. EIS results demonstrate that the MSO5 coating possesses the highest coating resistance and charge transfer resistance, indicating optimal initial barrier performance. The study reveals that the difference in cyclic corrosion resistance essentially originates from the coating’s ability to regulate selective oxidation behavior at the early corrosion stage and the subsequent film evolution process. The MSO5 coating, owing to the dispersed nano-Cr2O3 phase in its oxygen-containing outer layer,promotes the rapid establishment of a protective film, suppresses excessive formation of non-protective Ni and Co oxides, and maintains film continuity and stability during cyclic exposure, thereby significantly enhancing its corrosion resistance in the alternating salt spray—high-temperature environment.
Last Update: 2026-06-30