https://scholars.lib.ntu.edu.tw/handle/123456789/576884
標題: | Microstructural and electrochemical characterization of the passive film on a 50-kg hot rolled FeCrNiCoMn high entropy alloy | 作者: | Hsu K.-M CHAO-SUNG LIN |
關鍵字: | Auger electron spectroscopy; Corrosion resistance; Corrosive effects; Entropy; Grain boundaries; High-entropy alloys; Hot rolling; Scanning electron microscopy; Segregation (metallography); Sulfuric acid; Transmissions; Auger electron spectroscopies (AES); Compositional segregation; Deformation defects; Electrochemical characterizations; Interdendritic segregation; Mechanical properties at cryogenic temperatures; Scanning transmission electron microscopy; Transmission electron; High resolution transmission electron microscopy | 公開日期: | 2021 | 卷: | 26 | 來源出版物: | Materials Today Communications | 摘要: | FeCrNiCoMn high entropy alloy has outstanding mechanical properties at cryogenic temperature, and the related articles surge recently. However, the studies of large-scale FeCrNiCoMn alloys have not yet been reported. This work detailed the microstructure and corrosion behavior associated with the compositional segregation of a 50-kg FeCrNiCoMn in 0.5 M H2SO4 in the form of as-cast, hot-rolled, annealed, and homogenized alloys. Interdendritic segregation was observed in the central and columnar zones of as-cast FeCrNiCoMn, where Mn was the critical element trigging the corrosion. The annealing at 900 °C for 1.5 h effectively improved the general corrosion resistance and passivity of the partially-recrystallized FeCrNiCoMn, whereas the complete homogenizing at 1200 °C for 24 h did not further improve the passivity. The structure of the passive film was characterized using Auger electron spectroscopy (AES), high-resolution transmission electron (HRTEM), and scanning transmission electron microscopy (STEM). The AES results show that the passive film on the Mn-rich and Mn-poor regions had a similar composition. Like 304 L SS, the homogenized FeCrNiCoMn had the passive film enriched of Cr and with Ni enrichment beneath the surface. The passive film on homogenized FeCrNiCoMn was amorphous based on HRTEM and the thickness was estimated to be 1.66 nm by STEM. Finally, the corrosion behavior of the distinct FeCrNiCoMn alloys was discussed in detail based on the effect of casting defects, composition segregation, deformation defects, grain boundaries, and Mn-related oxide/sulfide inclusions. ? 2020 Elsevier Ltd |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098222642&doi=10.1016%2fj.mtcomm.2020.101979&partnerID=40&md5=bece6b4861b71875262d345109115fdd https://scholars.lib.ntu.edu.tw/handle/123456789/576884 |
ISSN: | 23524928 | DOI: | 10.1016/j.mtcomm.2020.101979 |
顯示於: | 材料科學與工程學系 |
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