Optimization of High Temperature Hoop Creep Response in ODS-Fe3Al Tubes
Conference
·
OSTI ID:835677
Oxide dispersion strengthened (ODS) Fe3Al alloys are currently being developed for heat-exchanger tubes for eventual use at operating temperatures of up to 1100 C in the power generation industry. The development challenges include (a) efforts to produce thin walled ODS-Fe3Al tubes, employing powder extrusion methodologies, with (b) adequate increased strength for service at operating temperatures to (c) mitigate creep failures by enhancing the as-processed grain size. A detailed and comprehensive research and development methodology is prescribed to produce ODS-Fe3Al thin walled tubes. Current single step extrusion consolidation methodologies typically yield 8ft. lengths of 1-3/8 inch diameter, 1/8 inch wall thickness ODS-Fe3Al tubes. The process parameters for such consolidation methodologies have been prescribed and evaluated as being routinely reproducible. Recrystallization treatments at 1200 C produce elongated grains (with their long axis parallel to the extrusion axis), typically 200-2000 {micro}m in diameter, and several millimeters long. The dispersion distribution is unaltered on a micro scale by recrystallization, but the high aspect ratio grain shape typically obtained limits grain spacing and consequently the hoop creep response. Improving hoop creep in ODS-alloys requires an understanding and manipulating the factors that control grain alignment and recrystallization behavior. Current efforts are focused on examining the processing dependent longitudinal vs. transverse creep anisotropy, and exploring post-extrusion methods to improve hoop creep response in ODS-Fe3Al alloy tubes. In this report we examine the mechanisms of hoop creep failure and describe our efforts to improve creep performance via variations in thermal-mechanical treatments.
- Research Organization:
- University of California - San Diego, La Jolla, CA; Oak Ridge National Lab., Oak Ridge, TN (US)
- Sponsoring Organization:
- USDOE Office of Fossil Energy (FE) (US)
- OSTI ID:
- 835677
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxide Dispersion Strengthened Fe3Al-Based Alloy Tubes: Application Specific Development for the Power Generation Industry
Oxide-Dispersion-Strengthened Fe3Al-Based Alloy Tubes: Application-Specific Development for the Power Generation Industry
CROSS-ROLL FLOW FORMING OF ODS ALLOY HEAT EXCHANGER TUBES FOR HOOP CREEP ENHANCEMENT
Technical Report
·
Thu Feb 07 23:00:00 EST 2002
·
OSTI ID:814126
Oxide-Dispersion-Strengthened Fe3Al-Based Alloy Tubes: Application-Specific Development for the Power Generation Industry
Technical Report
·
Fri Jul 20 00:00:00 EDT 2001
·
OSTI ID:814450
CROSS-ROLL FLOW FORMING OF ODS ALLOY HEAT EXCHANGER TUBES FOR HOOP CREEP ENHANCEMENT
Technical Report
·
Tue Aug 31 00:00:00 EDT 2004
·
OSTI ID:837878