Creep-fatigue strength of long-term post-service 2 ter dot 1/4 Cr-1 ter dot Mo steel and remaining life estimation
- Dept. of Mechanical Engineering, Nagaoka Univ. of Technology, Tomioka, Nagaoka (JP)
This paper reports on creep-fatigue strength of post-service 2 {center dot} 1/4 Cr-1 {center dot} Mo steel used for about one hundred-thousand hours in a fossil fuel power plant. The creep-fatigue strength of the post-service material was lower than that of the virgin material, whereas it was comparable to that of thermally aged material, which was artificially exposed at high temperature for a long time so that it had an equivalent value of the Larson-Miller parameter to the post-service material. The nondestructive detection of the long-term degradation damage due to long-term thermal aging, as well as due to creep-fatigue, was also investigated by applying an ultrasonic technique. It was found that the energy attenuation coefficient, {alpha}, which is defined by the ratio of input to output energies of a longitudinal ultrasonic wave, had a good correlation with creep-fatigue damage in the virgin, aged and post-service materials; and hence, {alpha} was a successful parameter to detect creep-fatigue damage. Based on the results thus obtained, a new remaining life estimation method for creep-fatigue of in-service high-temperature materials was proposed. The application of the method to the post-service material tested gave good predicted results.
- OSTI ID:
- 5133328
- Journal Information:
- Journal of Pressure Vessel Technology; (United States), Journal Name: Journal of Pressure Vessel Technology; (United States) Vol. 113:4; ISSN JPVTA; ISSN 0094-9930
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
200104 -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
AGING
CHROMIUM-MOLYBDENUM STEELS
CREEP
FATIGUE
FLEXURAL STRENGTH
FOSSIL-FUEL POWER PLANTS
IN-SERVICE INSPECTION
INSPECTION
LIFETIME
MATERIALS TESTING
MECHANICAL PROPERTIES
PHYSICAL PROPERTIES
POWER PLANTS
RELIABILITY
SERVICE LIFE
STRESS ANALYSIS
STRESSES
TESTING
THERMAL CYCLING
THERMAL POWER PLANTS
THERMAL STRESSES
THERMODYNAMIC PROPERTIES