Effect of chromium and aluminum on the mechanical and oxidation properties of an iron-nickel-base superalloy. [Cr varied from 12-0 wt % and Al from 1. 5-6 wt %]

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5308443

Schuon, S R ^[1]

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1. NASA Lewis Research Center, Cleveland, OH (USA)

The effects of Cr and Al on the mechanical and oxidation properties of a series of {gamma}{prime} strengthened alloys based on CG27 were studied. The series was based on the reduction of Cr from 12 w/o to Ow/o. Aluminum was increased from 1.5w/oAl to 6w/o. Alloys were tested in tension at RT and 760C and stress rupture tested at 760C, 172 MPa and 276 MPa. Alloys were oxidized for 200/1-1 hr cycles at 870C. A reduction in Cr to 4w/o was possible if the Al content was increased to 3w/o. This conclusion is based on the following results. The stress rupture life of the alloys reached a maximum at 4w/o Cr+3w/oAl then dropped at higher levels of Cr+Al. Since {gamma}{prime} coherency had little effect on strength, {gamma}{prime} dispersion and solid solution strengthening were the principle modes of strengthening. The oxidation attack parameter, K{sub a}, decreased with increasing w/o Cr+Al in each group. As a group, 3w/oAl alloys had the lowest K{sub a}. Spalling, due to diffusion induced grain growth was controlled by the overall Cr+Al levels. A 66 percent reduction in Cr content from CG27 was achieved.

• OSTI ID: 5308443
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMIUM
CORROSION RESISTANCE
CRYSTAL GROWTH
DIFFUSION
ELEMENTS
FAILURES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
METALLURGICAL EFFECTS
METALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
OXIDATION
RUPTURES
STRESSES
TESTING
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE