Characterization of pack cemented Ni(2)Al(3 )coating exposed to KCl(s) induced corrosion at 600 degrees C

• Oxidation of Ni2Al3 produced by pack aluminizing of pure nickel was studied with and without 0.10 mg cm(-2) KCl(s) deposit in an environment containing 5% O-2, 40% H2O and 55% N-2 at 600 degrees C for up to 168 h. Oxide microstructure and composition was investigated by SEM/EDX, BIB, TEM and GDOES. Oxidised Ni2Al3 shows minimal weight gain, while adding KCl results in a small weight loss consistent with evaporation of KCl. On the surface of samples exposed to the gas environment only, a 30 nm oxide of Al oxide was present, but where KCl was present as deposit, 50-250 nm thick nodules form that are enriched in K, O and Al.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Korrosionsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Corrosion Engineering (hsv//eng)

Keyword

KCl

Nickel aluminide

high temperature corrosion

electron microscopy

600 degrees C

Publication and Content Type

art (subject category)

ref (subject category)