Adherence of oxide scale formed on Ni20Cr1Si alloys with small additions of rare earth elements

Role of Y in the oxidation resistance of CrAlYN coatings

“…Moreover, the protectiveness of nanostructured CrAlYN coatings [∼4-12 at.% of Al; ∼2-5 at.% of Y] deposited on P92 steel against steam oxidation at 650 • C was found to be comparable to conventional microstructured aluminides at much lower thickness than used for steam turbine components [21,22] the location of the metallic elements inside ternary or quaternary nitrides and their chemical state may have a significant influence on the oxidation behavior and protective mechanism. The structure of these CrAlYN coatings was studied in detail with the help of advanced microscopic and analytical techniques with nanometric spatial resolution.…”

Tribological behaviour at high temperature of hard CrAlN coatings doped with Y or Zr

“…Ytrium has been proposed to improve oxidation resistance beyond 1100ºC by segregation to the oxide scale grain boundaries, blocking fast diffusion paths [11,15,[18][19][20]. Moreover, the addition of a reactive element was suggested to reduce the accumulation of voids at the substrate/scale interface [21]; to improve the mechanical properties of the scale by modifying its structure [22] or to prevent the grain coarsening at elevated temperatures [23]. In a previous work we also confirmed the improved oxidation resistance of a CrAlYN coating in comparison to CrAlZrN [24].…”

The Effects of Pre-Oxidation and Alloy Chemistry of Austenitic Stainless Steels on Glass/Metal Sealing

“…In addition, longer oxidation times at high temperature could result in the eventual crystallization of the SiO 2 layer in samples from all of the heats. A transition from amorphous to crystalline SiO 2 was observed during oxidation of Fe-Si alloys at 1100°C and crystalline SiO 2 , in cristobalite form, has been reported for stainless steel oxidation at higher temperatures for longer times (1200°C) [32,33]. Based on several stainless steel oxidation studies, Stott et al [34] found that, in general, amorphous SiO 2 is favored at short times and low temperatures (transient oxidation) while crystalline forms of SiO 2 are prevalent at higher temperatures and longer times.…”