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The effect of niobium on the oxidation behaviour of fully Austenitic Fe‐15% Cr‐15%Ni stainless steels
Author(s) -
Ramanathan L. V.,
Pohl M.,
Padilha A. F.
Publication year - 1995
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.19950460203
Subject(s) - niobium , chromium , oxide , materials science , metallurgy , alloy , metal , austenite , isothermal process , iron oxide , inorganic chemistry , chemistry , microstructure , physics , thermodynamics
The influence of niobium content (0.5–2.0 wt.%) on the oxidation behaviour of Fe‐15% Cr‐15% Ni austenitic stainless steels has been studied by cyclic oxidation tests in air at different temperatures in the range 800–1200°C. The isothermal oxidation rate, the scaling index and the cumulative oxide loss decreased with increasing niobium content. X‐ray diffraction and fluorescence analysis of detached oxide scales revealed that the niobium in the alloy matrix facilitated the formation of chromium rich (Fe, Cr) 2 O 3 and niobium containing mixed oxide near the metal/metal oxide boundary, which decreased further oxidation. SEM/EDX investigations revealed that the external oxide changed from being predominantly iron rich iron‐chromium oxide to being chromium rich iron‐chromium oxide.