Influence of CrN surface compound on the initial stages of high temperature oxidation of ferritic stainless steel

• Published in: Applied surface science 2011-06, Vol.257 (17), p.7783-7791
• Main Authors: Ali-Löytty, H., Jussila, P., Hirsimäki, M., Valden, M.
• Format: Article
• Language: English
• Subjects: Annealing; Chromium nitride; Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Composition; defects and impurities; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Controlled atmospheres; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Ferritic stainless steels; Materials science; Oxidation; Oxides; Photoelectron spectroscopy; Photoemission and photoelectron spectra; Physics; Segregations; Solid surfaces and solid-solid interfaces; Stainless steels; Surface segregation; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Treatment of materials and its effects on microstructure and properties; Ultrahigh vacuum
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.04.029

► Evolution of surface compounds on Fe–17Cr was studied upon annealing and oxidation. ► CrN surface compound promotes the selective oxidation of Cr at elevated temperatures. ► Nitrogen is buried below the oxide layer as the oxidation proceeds. ► High-resolution photoelectron spectroscopy was used to identify different N species. Segregation phenomena and formation of surface compounds on Fe–17Cr (ferritic stainless steel) were studied at temperatures up to 800 °C upon annealing and kinetically controlled oxidation by photoelectron spectroscopy and inelastic electron background analysis. The results revealed the formation of a chromium nitride surface compound during annealing in ultrahigh vacuum at temperatures exceeding 527 °C. Surface enrichment of P, As, and other trace elements became more prominent at higher temperatures approaching 800 °C. It was found that nitrogen was buried below the surface oxide layer during oxygen exposure, yet it had little effect on the rate of oxidation. However, the formation of CrN surface compound promoted the selective oxidation of Cr initially, which is of great importance in processing and application environments involving high temperature and controlled atmosphere conditions.