Deformation and fracture of low alloy steels at high temperature

Technical Report · Thu Dec 01 04:00:00 EST 1988

DOI:https://doi.org/10.2172/5500858· OSTI ID:5500858

Marriott, D. L.; Stubbins, J. F.; Leckie, F. A.; Muddle, B.

This project formed part of the initiative in the AR TD program to characterize high temperature, time-dependent damage processes in low alloy steels, for use in the construction of coal-gasification plant. This project was broadly aimed at adding to the knowledge base for this bainitic form of 2.25Cr 1Mo steel, as it related to time-dependent performance at elevated temperature. Its original intention was to obtain information in specific grades of 2.25Cr 1Mo steel, in particular those containing reduced residual elements and microalloyed modifications, which were being considered as candidate materials at the time. This objective was subsequently modified, in the course of the contract period, to a more generic study of bainitic steel, using the 2.25Cr 1Mo material as a representative of the class. The main thrust of the project was directed initially at the detrimental effect of cyclic loading on creep resistance and manifesting itself in an apparently severe creep-fatigue interaction. Three subtasks were eventually identified. These are: a study of the evolution of microstructural changes in bainitic materials during steady load creep and under constant amplitude cyclic deformation, investigation of the effect of cyclic softening on the fatigue and creep strength of complex geometries, focusing on circumferentially notched bars, and investigation of the influence of environment as a possible cause of observed fatigue/elevated temperature interaction through its effects on crack initiation and propagation, using EDM notched specimens tested in air and vacuum. Results are discussed. 24 refs., 40 figs., 5 tabs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• Sponsoring Organization: DOE/FE
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5500858
• Report Number(s): ORNL/Sub-82-22239-01; UILU-ENG--88-4019; ON: DE90001274; CNN: 19X-22239WBS Element U1-3.3
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
20 FOSSIL-FUELED POWER PLANTS
200104 -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHROMIUM ALLOYS
CREEP
CRYSTAL STRUCTURE
DEFORMATION
DOCUMENT TYPES
FAILURES
FATIGUE
FRACTURES
HIGH TEMPERATURE
MECHANICAL PROPERTIES
MICROSTRUCTURE
MOLYBDENUM ALLOYS
PROGRESS REPORT
STRAIN RATE