Microstructural evolution in a ferritic-martensitic stainless steel and its relation to high-temperature deformation and rupture models
The ferritic-martensitic stainless steel HT-9 exhibits an anomalously high creep strength in comparison to its high-temperature flow strength from tensile tests performed at moderate rates. A constitutive relation describing its high-temperature tensile behavior over a wide range of conditions has been developed. When applied to creep conditions the model predicts deformation rates orders of magnitude higher than observed. To account for the observed creep strength, a fine distribution of precipitates is postulated to evolve over time during creep. The precipitate density is calculated at each temperature and stress to give the observed creep rate. The apparent precipitation kinetics thereby extracted from this analysis is used in a model for the rupture-time kinetics that compares favorably with observation. Properly austenitized and tempered material was aged over times comparable to creep conditions, and in a way consistent with the precipitation kinetics from the model. Microstructural observations support the postulates and results of the model system. 16 refs., 10 figs.
- Research Organization:
- Argonne National Lab., IL (USA)
- Sponsoring Organization:
- DOE/NE
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 6412280
- Report Number(s):
- CONF-910202-2; ON: DE91006471
- Resource Relation:
- Conference: Annual meeting and exhibition of the Minerals, Metals and Materials Society, New Orleans, LA (USA), 17-21 Feb 1991
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
STAINLESS STEELS
CREEP
TENSILE PROPERTIES
DEFORMATION
KINETICS
MICROSTRUCTURE
PRECIPITATION
RUPTURES
ULTIMATE STRENGTH
ALLOYS
CRYSTAL STRUCTURE
FAILURES
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
SEPARATION PROCESSES
STEELS
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies