Multi-Phase High Temperature Alloys: Exploration of Alumina-Forming, Creep-Resistant Austenitic Stainless Steels
Abstract
Work in 2007 focused on the development of a new class of heat-resistant austenitic stainless steel alloys which achieved a unique combination of high-temperature creep strength and excellent oxidation resistance via protective Al{sub 2}O{sub 3} scale formation. Strengthening is achieved via the formation of stable nano NbC carbides with/without Fe{sub 2}Nb and related intermetallic phase dispersions, with controlled levels of Al to enable Al{sub 2}O{sub 3} scale formation in both air and air + water vapor environments up to {approx}800-900 C. The developed alloys exhibit comparable creep resistance to that of the best commercial heat-resistant austenitic stainless steels, and the protective Al{sub 2}O{sub 3} scale formation provides oxidation resistance superior to that of advanced Cr{sub 2}O{sub 3}-forming heat-resistant austenitic alloys. Preliminary screening also indicated that the developed Al-modified alloys were amenable to welding.
- Authors:
- ORNL
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- FE USDOE - Office of Fossil Energy (FE)
- OSTI Identifier:
- 931001
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Conference
- Resource Relation:
- Conference: 21st Annual Conference on Fossil Energy Materials, Knoxville, TN, USA, 20070430, 20070502
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; AIR; ALLOYS; CARBIDES; CREEP; EXPLORATION; OXIDATION; STAINLESS STEELS; WATER VAPOR; WELDING
Citation Formats
Brady, Michael P, Yamamoto, Yukinori, Lu, Zhao Ping, Maziasz, Philip J, Santella, Michael L, and Pint, Bruce A. Multi-Phase High Temperature Alloys: Exploration of Alumina-Forming, Creep-Resistant Austenitic Stainless Steels. United States: N. p., 2007.
Web.
Brady, Michael P, Yamamoto, Yukinori, Lu, Zhao Ping, Maziasz, Philip J, Santella, Michael L, & Pint, Bruce A. Multi-Phase High Temperature Alloys: Exploration of Alumina-Forming, Creep-Resistant Austenitic Stainless Steels. United States.
Brady, Michael P, Yamamoto, Yukinori, Lu, Zhao Ping, Maziasz, Philip J, Santella, Michael L, and Pint, Bruce A. Mon .
"Multi-Phase High Temperature Alloys: Exploration of Alumina-Forming, Creep-Resistant Austenitic Stainless Steels". United States.
doi:.
@article{osti_931001,
title = {Multi-Phase High Temperature Alloys: Exploration of Alumina-Forming, Creep-Resistant Austenitic Stainless Steels},
author = {Brady, Michael P and Yamamoto, Yukinori and Lu, Zhao Ping and Maziasz, Philip J and Santella, Michael L and Pint, Bruce A},
abstractNote = {Work in 2007 focused on the development of a new class of heat-resistant austenitic stainless steel alloys which achieved a unique combination of high-temperature creep strength and excellent oxidation resistance via protective Al{sub 2}O{sub 3} scale formation. Strengthening is achieved via the formation of stable nano NbC carbides with/without Fe{sub 2}Nb and related intermetallic phase dispersions, with controlled levels of Al to enable Al{sub 2}O{sub 3} scale formation in both air and air + water vapor environments up to {approx}800-900 C. The developed alloys exhibit comparable creep resistance to that of the best commercial heat-resistant austenitic stainless steels, and the protective Al{sub 2}O{sub 3} scale formation provides oxidation resistance superior to that of advanced Cr{sub 2}O{sub 3}-forming heat-resistant austenitic alloys. Preliminary screening also indicated that the developed Al-modified alloys were amenable to welding.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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On the Loss of Protective Scale Formation in Creep-Resistant, Alumina-Forming Austenitic Stainless Steels at 900?aC in Air
A family of creep-resistant, Al2O3-forming austenitic (AFA) stainless steels was recently developed. The alloys exhibit excellent oxidation resistance up to 800 aC, but are susceptible to internal attack of Al at higher temperatures. In the present work, higher levels of Ni, Cr, Al, and Nb additions were found to correlate with improved oxidation behavior at 900 aC in air. The alloys generally appeared to be initially capable of external Al2O3 scale formation, with a subsequent transition to internal attack of Al (internal oxidation and internal nitridation) that is dependent on alloy composition. Compositional profiles at the alloy/scale interface suggest thatmore » -
Overview of strategies for high-temperature creep and oxidation resistance of alumina-forming austenitic stainless steels
A family of creep-resistant, alumina-forming austenitic (AFA) stainless steel alloys is under development for structural use in fossil energy conversion and combustion system applications. The AFA alloys developed to date exhibit comparable creep-rupture lives to state-of-the-art advanced austenitic alloys, and superior oxidation resistance in the {approx}923 K to 1173 K (650 C to 900 C) temperature range due to the formation of a protective Al{sub 2}O{sub 3} scale rather than the Cr{sub 2}O{sub 3} scales that form on conventional stainless steel alloys. This article overviews the alloy design approaches used to obtain high-temperature creep strength in AFA alloys via considerationsmore »