Room temperature strains in Cr sub 2 O sub 3 scales formed at elevated temperatures on Ni-25wt%Cr and Y- and Al-doped Ni-25%Cr

Journal Article · Wed May 01 00:00:00 EDT 1991 · Acta Metallurgica; (United States)

OSTI ID:7177272

Hou, P Y ^[1]; Stringer, J ^[2]

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1. Materials and Chemical Sciences Div., Lawrence Berkeley Lab., Berkeley, CA (US)
2. Electric Power Research Inst., Palo Alto, CA (US)

This paper reports that Ni-25wt%Cr Ni-25wt%Cr-1wt%Al and Ni-25wt%Cr-0.2wt%Y alloys were oxidized at 1000{degrees}C in O{sub 2} to form similar thicknesses of Cr{sub 2}O{sub 3} scales. After cooling to ambient temperatures, the residual strains in these oxide films were measured using X-ray diffraction, and qualitative indications of the interfacial strength were obtained using a micro-indentation technique. compressive elastic strains of the order of 0.4% were measured on the Y- and the Al-doped alloys. This value agrees well with calculated thermal strains which arose form cooling. Only 0.1% compressive elastic strains were observed for the undoped Ni-25Cr alloy. Localized scale buckling and separation from the substrate is believed to have allowed relaxation of the strain in this case. The Y- and the Al-doped alloys on the other hand, have extremely strong scale/alloy interfaces, and therefore were able to retain higher strain levels.

• OSTI ID: 7177272
• Journal Information: Acta Metallurgica; (United States), Vol. 39:5; ISSN 0001-6160
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
OXIDATION
CHROMIUM ALLOYS
CHROMIUM OXIDES
THICKNESS
NICKEL BASE ALLOYS
YTTRIUM ALLOYS
ALUMINIUM ADDITIONS
BINARY ALLOY SYSTEMS
COOLING
DOPED MATERIALS
ELASTICITY
STRAINS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 1000-4000 K
TERNARY ALLOY SYSTEMS
X-RAY DIFFRACTION
YTTRIUM ADDITIONS
ALLOY SYSTEMS
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
COHERENT SCATTERING
DIFFRACTION
DIMENSIONS
MATERIALS
MECHANICAL PROPERTIES
NICKEL ALLOYS
OXIDES
OXYGEN COMPOUNDS
SCATTERING
TEMPERATURE RANGE
TENSILE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion
360203 - Ceramics
Cermets
& Refractories- Mechanical Properties