| dc.description.abstract | Tutorial 16: In today's market place, a large percentage of oil refinery, petrochemical, and power generation plants throughout the world have been trying to reduce their operation cost by extending the service life of their critical machines, such as steam turbines and hot gas expanders, beyond the design life criteria. The key ingredient in plant life extension is Remaining Life Assessment Technology. This paper will outline the Remaining Life Assessment procedures, and review the various damage mechanisms such as creep, fatigue, creep-fatigue and various embrittlement mechanisms that can occur in these machines. Also highlighted will be the various testing methods for determining remaining life or life extension of components such as high precision SRT (Stress Relaxation Test), which determines creep strength, and CDR (Constant Displacement Rate) Test, which evaluates fracture resistance. Other tests such as replication/microstructure analysis and toughness tests will be reviewed for assessment of the remaining life or life extension of the components. Use of computer software will be highlighted showing how creep-life, fatigue-life and creep/fatigue-life calculations can be performed. Actual examples of remaining life assessment testing performed on steam turbines and hot gas expander components are provided. | en |
