Findings on creep-fatigue damage in pressure parts of long-term service-exposed thermal power plants

Journal Article · Thu Aug 01 04:00:00 EDT 1985 · J. Pressure Vessel Technol.; (United States)

DOI:https://doi.org/10.1115/1.3264447· OSTI ID:6098341

Masuyama, F; Hanzda, H; Nanjo, F; Setoguchi, K

The increase of long-term service exposure to thermal power plants, the tendency toward intermediate and cyclic operation to meet the change in electric power demand and supply situation, and the requirement to develop higher-temperature and higher-pressure plants have led to increasing attention towards the reliability improvement. This paper presents findings from field experiences of cracking or failure and two types of damage analyses - (1) creep-fatigue damage analysis based on the life fraction rule and (2) metallurgical damage analysis - of boiler pressure parts that have been exposed to long-term elevated temperature service. The field experiences are (1) cracking or failure of thick-walled Type 316 stainless steel pressure parts in the main steam line of an ultra-supercritical thermal power plant and (2) dissimilar metal weld joints for boiler tubing. The creep-fatigue damage analysis of these pressure parts showed a reasonable correspondence with the field experience. According to the creep-fatigue damage analysis and the metallurgical damage analysis, most of damage was restrained creep mode phenomenon without deformation. The creep damage was composed of metallurgical damage and mechanical damage such as microvoids and structural defects. One method of simulating field experienced creep damage was proposed and performed. As a result, the process of creep voids being generated and growing into cracks without deformation was successfully observed. Also a review of the current status of nondestructive detecting methods of creep damage suggests that detecting the creep voids metallurgically is more practical at the present time than doing so analyzing the changes in physical properties of the material.

• Research Organization: Nagasaki Technical Institute, Mitsubishi Heavy Industries, Ltd., Nagasaki
• OSTI ID: 6098341
• Journal Information: J. Pressure Vessel Technol.; (United States), Journal Name: J. Pressure Vessel Technol.; (United States) Vol. 107:3; ISSN JPVTA
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104* -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
BOILERS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CONTAINERS
CORROSION RESISTANT ALLOYS
CRACKS
CREEP
DAMAGE
FATIGUE
FIELD TESTS
FRACTURE PROPERTIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
METALLURGY
MOLYBDENUM ALLOYS
NICKEL ALLOYS
PHYSICAL METALLURGY
PHYSICAL PROPERTIES
POWER PLANTS
PRESSURE VESSELS
SERVICE LIFE
SIMULATION
STAINLESS STEEL-316
STAINLESS STEELS
STEELS
TESTING
THERMAL POWER PLANTS
WELDED JOINTS