Characterization of the oxide films formed on low temperature sensitized AISI 321 stainless steel with different strain levels in elevated temperature borate buffer solution

Luo Hongyun, Zhang Yubo, Li Hongdou, Lv Jinlong, Ma Yue

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

The effect of strain and low temperature sensitization on corrosion resistance of AISI 321 stainless steel in elevated borate buffer solution was investigated. The study found that the AISI 321 stainless steel with 20% strain showed the lowest degree of sensitization due to the fact that sample with 20% strain had high dislocation density which promoted chromium diffusion and a small amount of α'-martensites. The results from electrochemical impedance spectroscopy indicated that sensitized sample with 20% strain showed the best corrosion resistance after immersion test at 290 °C. A good agreement was found between the electrochemical impedance spectroscopy and the degree of sensitization. The oxide film was composed of three layers according to the results of the XPS and Raman spectra. In addition, the outer part compositions of the oxide film were mainly γ-Fe2O3and Fe-Cr spinel and iron hydroxide, while the inner and intermediate layers were mainly Fe-Cr spinel and the mixtures of the oxides of Fe, Cr, Ni. The ratio of hydroxide in oxide film increased due to large strain, especially for chromium hydroxide. Mott-Schottky analysis showed that more hydroxides induced more donor and acceptor concentrations in oxide film. More hydroxides reduced corrosion resistance of oxide film.

Original languageEnglish
Pages (from-to)1235-1243
Number of pages9
JournalJournal of Alloys and Compounds
Volume696
DOIs
Publication statusPublished - 2017

Keywords

  • Deformation
  • EIS
  • Oxide film
  • Sensitization
  • XPS

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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