The Initial Oxide Scale Development on a Model FeNiCrAl Alloy at 900 degrees C in Dry and Humid Atmosphere: A Detailed Investigation
Artikel i vetenskaplig tidskrift, 2014

The investigated alumina forming FeNiCrAl model alloy shows protective oxidation behavior in dry and humid environment at 900 A degrees C. Hence, this type of alloy may replace conventional chromia forming austenitic alloys in aggressive oxidizing/reducing environments. A detailed investigation of the oxide scale development reveals a complex initial scale development. Firstly, at alloy grain boundaries, a thin Al rich oxide forms which is replaced by transient alumina platelets in dry and equiaxed alpha-Al2O3 crystallites in humid atmosphere. The scale at alloy grain centers develops via a layered scale of external chromia:Fe/Ni metal inclusions:internal alumina to a layered external spinel:internal alumina scale in dry atmosphere. In humid condition an additional oxide feature appears on the center of large alloy grains i.e. thick oxide protrusions. Despite the initially different phase compositions a continuous protective alpha-Al2O3 scale forms both atmospheres.

fe-ni-cr

high-temperature oxidation

o-2

additions

austenitic stainless-steels

resistance

al alloys

behavior

Författare

Josefin Hall

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Kristina M Hellström

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Jan-Erik Svensson

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Mats Norell

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

M. Lundberg

Sandvik Materials Technology

T. Helander

Sandvik Materials Technology

Lars-Gunnar Johansson

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Oxidation of Metals

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

Vol. 82 225-247

Ämneskategorier

Miljövetenskap

DOI

10.1007/s11085-014-9489-0