Effects of minor alloying elements on the welding behavior of FeA1 alloys for structural and weld-overlay cladding applications

Journal Article · Mon Dec 14 23:00:00 EST 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90029-E· OSTI ID:6731235

Maziasz, P J; Goodwin, G M; Liu, C T; David, S A ^[1]

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1. Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

This paper reports that recent properties studies of FeAl alloys for high-temperature structural applications have been expanded to include improved weldability. a base FeAl (B2-phase) binary allow composition of Fe-36 at. % Al appears to offer a nearly optimum combination of oxidation/corrosion resistance and mechanical behavior. FeAl alloys show outstanding oxidation resistance to temperatures of [gt] 1100[degrees]C, corrosion resistance in sulfidizing environments at 800-900[degrees]C, and excellent resistance to corrosion in molten nitrate salts at 650[degrees]C (1-3). While binary FeAl alloys generally have poor room-temperature ductility, and are weak above about 600[degrees]C, alloying effects can significantly improve their mechanical properties at room- and high-temperatures. Furthermore, studies of room-temperature brittleness of FeAl alloys have shown that hydrogen released at crack-tips from moisture in air causes low ductility at room-temperature, so that these alloys are not inherently brittle, but are sensitive to environmental effects. Results of systematic studies of minor element alloying effects have shown that small additions of molybdenum (0. 2 at. %) improve oxidation resistance at 1000[degrees]C, combined additions of small amounts of zirconium and boron (0. 05 at. % and 0. 24 at. %, respectively) produce room-temperature ductility [gt] 10%, and small additions of molybdenum (0. 2 at. %) improve tensile and creep-rupture strength at 600[degrees]C, especially when combined with Zr + B or chromium plus boron. However, preliminary results show that such alloys hot-crack during welding. Because there is almost no data on welding of FeAl alloys, this study was undertaken to: identify the alloying elements associated with the hot-cracking, and attempt to minimize or eliminate hot-cracking during welding by controlling the minor alloying additions.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6731235
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 27:12; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CLADDING
CORROSION RESISTANCE
DEPOSITION
ENVIRONMENTAL EFFECTS
FABRICATION
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
JOINING
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
OXIDATION
PHYSICAL PROPERTIES
SURFACE COATING
TESTING
THERMODYNAMIC PROPERTIES
WEAR RESISTANCE
WELDING