Life assessment of boiler pressure parts. Volume 3, Heavy section crack initiation and propagation: Final report
- General Atomics, San Diego, CA (United States)
- Babcock and Wilcox Co., Alliance, OH (United States)
For thick section pressure retaining components in elevated temperature service in fossil-fired power plants, the life limiting damage mechanisms are generally associated with crack initiation and propagation involving both creep and fatigue. A methodology has been developed for life assessment of such components involving the calculation of key stresses and strains and the use of these values to estimate crack initiation and propagation. The methodology has been developed for cracking in the ligaments and other regions of headers and in piping. The methodology is embodied in the computer code BLESS (Boiler Life Estimation and Simulation System). This volume of the final report for project RP2253-10 contains background information on the modes of damage observed in headers, stress analyses performed to identify damage causes, field observations made, destructive examination carried out to identify damage mechanisms, and the integration of these factors into the BLESS code. A user`s manual is provided as a separate volume (Volume 4). The methodology developed utilizes steam temperature, pressure, and flow rate data which are normally available to the plant operator. These data are used in the form of time histories and resulting stress/strain cycles are calculated for critical regions of the component. Crack initiation criteria based on creep-fatigue damage and on notches caused by oxide cracking are described. Crack propagation estimation techniques are employed covering creep and fatigue. Validation data, gathered but not yet fully utilized, are described. A key feature of the methodology is that the complete service history, past, present, and future can be examined.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); General Atomics, San Diego, CA (United States); Babcock and Wilcox Co., Alliance, OH (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 10132001
- Report Number(s):
- EPRI-TR-103377-V3; ON: UN94007942
- Resource Relation:
- Other Information: PBD: Nov 1993
- Country of Publication:
- United States
- Language:
- English
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