Increased strengthening of austenitic alloys through dual aging
A study of the effect of solution treatment, single and duplex isothermal aging heat treatments on an Fe-Ni-Ti-Al austenitic alloy hardened by ..gamma..' precipitation is reported. Sequential heat treatments were performed and studied in order to develop a systematic process for achieving very high strength austenite through thermal processing alone. Room temperature tensile tests were carried out. Alloys receiving double aging treatments were found to achieve mechanical properties superior to those aged at a given temperature. An optimum level of yield strength (172 Ksi) along with good elongation (20%) was obtained from a two-step aging process. Structural examination indicated that overaging was retarded by secondary aging. The formation and growth of cellular precipitates were suppressed. Resistivity changes were measured on wire specimens to study the early stages of precipitation. Resistivity peaks were observed during secondary aging indicating evidence of secondary precipitation.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6550508
- Report Number(s):
- LBL-8000
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-strength austenitic alloys for generator retaining rings. Interim report
Intermetallic Strengthened Alumina-Forming Austenitic Steels for Energy Applications
Related Subjects
ALUMINIUM ALLOYS
HEAT TREATMENTS
IRON BASE ALLOYS
NICKEL ALLOYS
TITANIUM ALLOYS
AGE HARDENING
AGING
AUSTENITIC STEELS
PRECIPITATION HARDENING
TENSILE PROPERTIES
YIELD STRENGTH
ALLOYS
HARDENING
IRON ALLOYS
MECHANICAL PROPERTIES
STEELS
360101* - Metals & Alloys- Preparation & Fabrication
360103 - Metals & Alloys- Mechanical Properties