Response of ferritic steels to nonsteady loading at elevated temperatures
Abstract
High-temperature operating experience is lacking in pressure vessel materials that have strength levels above 586 MPa. Because of their tendency toward strain softening, we have been concerned about their behavior under nonsteady loading. Testing was undertaken to explore the extent of softening produced by monotonic and cyclic strains. The specific materials included bainitic 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel containing vanadium, titanium, and boron, and a martensitic 9Cr-1Mo-V-Nb steel. Tests included tensile, creep, variable stress creep, relaxation, strain cycling, stress cycling, and non-isothermal creep ratchetting experiments. We found that these steels had very low uniform elongation and exhibited small strains to the onset of tertiary creep compared to annealed 2 1/4Cr-1Mo steel. Repeated relaxation test data also indicated a limited capacity for strain hardening. Reversal strains produced softening. The degree of softening increased with increased initial strength level. We concluded that the high strength bainitic and martensitic steels should perform well when used under conditions where severe cyclic operation does not occur.
- Authors:
- Publication Date:
- Research Org.:
- Oak Ridge National Lab., TN (USA)
- OSTI Identifier:
- 6695064
- Report Number(s):
- CONF-840647-23-Draft
ON: DE84014280
- DOE Contract Number:
- AC05-84OR21400
- Resource Type:
- Conference
- Resource Relation:
- Conference: ASME pressure vessel and piping conference, San Antonio, TX, USA, 17 Jun 1984; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; CHROMIUM-MOLYBDENUM STEELS; MECHANICAL PROPERTIES; STRAIN SOFTENING; PRESSURE VESSELS; MATERIALS TESTING; CREEP; FATIGUE; HIGH TEMPERATURE; NIOBIUM ADDITIONS; STRESS RELAXATION; TEMPERATURE DEPENDENCE; TENSILE PROPERTIES; TITANIUM ADDITIONS; VANADIUM ADDITIONS; ALLOYS; CHROMIUM ALLOYS; CHROMIUM STEELS; CONTAINERS; IRON ALLOYS; IRON BASE ALLOYS; NIOBIUM ALLOYS; RELAXATION; STEELS; TESTING; TITANIUM ALLOYS; VANADIUM ALLOYS; 360103* - Metals & Alloys- Mechanical Properties
Citation Formats
Swindeman, R W. Response of ferritic steels to nonsteady loading at elevated temperatures. United States: N. p., 1984.
Web.
Swindeman, R W. Response of ferritic steels to nonsteady loading at elevated temperatures. United States.
Swindeman, R W. 1984.
"Response of ferritic steels to nonsteady loading at elevated temperatures". United States. https://www.osti.gov/servlets/purl/6695064.
@article{osti_6695064,
title = {Response of ferritic steels to nonsteady loading at elevated temperatures},
author = {Swindeman, R W},
abstractNote = {High-temperature operating experience is lacking in pressure vessel materials that have strength levels above 586 MPa. Because of their tendency toward strain softening, we have been concerned about their behavior under nonsteady loading. Testing was undertaken to explore the extent of softening produced by monotonic and cyclic strains. The specific materials included bainitic 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel containing vanadium, titanium, and boron, and a martensitic 9Cr-1Mo-V-Nb steel. Tests included tensile, creep, variable stress creep, relaxation, strain cycling, stress cycling, and non-isothermal creep ratchetting experiments. We found that these steels had very low uniform elongation and exhibited small strains to the onset of tertiary creep compared to annealed 2 1/4Cr-1Mo steel. Repeated relaxation test data also indicated a limited capacity for strain hardening. Reversal strains produced softening. The degree of softening increased with increased initial strength level. We concluded that the high strength bainitic and martensitic steels should perform well when used under conditions where severe cyclic operation does not occur.},
doi = {},
url = {https://www.osti.gov/biblio/6695064},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Apr 01 00:00:00 EST 1984},
month = {Sun Apr 01 00:00:00 EST 1984}
}