A Comparison of the Oxidation and Nitridation Properties of Selected Chromia- and Alumina-Forming Alloys at 800 degrees C
Journal article, 2022

Three FeCrAl alloys and two chromia-formers (a stainless steel, and a Ni-base alloy) have been exposed in four environments (dry air, air + 20% H2O, 20% H-2 + 20% H2O + Ar and 95% N-2 + 5% H-2) for 168 h at 800 degrees C. The corroded samples were investigated by SEM/EDS, XRD and gravimetry, and the formation of CrO2(OH)(2)(g) was measured as a function of time using a denuder technique. The Fe-base alloy formed a Cr-rich protective oxide scale in dry air and wet air but suffered break-away oxidation in 20% H-2 + 20% H2O + Ar. In contrast, the Ni-base alloy suffered extensive NiO formation and internal oxidation in dry air and wet air but formed a protective chromia scale in 20% H-2 + 20% H2O. All three FeCrAl alloys formed protective alumina scales in dry air, wet air and 20% H-2 + 20% H2O + Ar. The FeCrAl alloy Kanthal APMT was severely nitrided in the 95% N-2 + 5% H-2 environment due to defects in the oxide scale associated with RE-rich inclusions which allowed nitrogen to enter the alloy. In contrast, the two Cr-lean FeCrAl alloys Kanthal EF101 and Kanthal EF100 did not suffer nitridation at all.

Cr-evaporation

High temperature corrosion

Stainless steels

Ni-base alloys

FeCrAl alloys

Nitridation

Author

Tommy Sand

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Jesper Liske

Chalmers, Chemistry and Chemical Engineering, Energy and Material

T. Helander

Kanthal AB

Jan-Erik Svensson

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Lars-Gunnar Johansson

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Oxidation of Metals

0030-770X (ISSN) 1573-4889 (eISSN)

Vol. 98 1-2 163-178

Subject Categories

Other Materials Engineering

Metallurgy and Metallic Materials

Corrosion Engineering

DOI

10.1007/s11085-022-10117-3

More information

Latest update

3/7/2024 9