Properties of Cr-Mo steels after long-term high-temperature service
- CC Technologies, Columbus, OH (United States)
- Electric Power Research Institute, Palo Alto, CA (United States)
The mechanical properties of 2-1/4Cr-1Mo9 and 1-1/4cr-1/2Mo steels can be significantly altered by long-term service at elevated temperatures in the creep range. These property changes are caused by thermal and mechanically induced aging. The effects of such material aging should be considered in assessing the structural integrity and remaining service life of piping and pressure vessels made from these Cr-Mo steels. Int the current study, mechanical properties data for these two steels after long-term service at typical steam-plant temperatures were collected, analyzed, and compared with similar data for new materials to quantify the degree of aging caused by high-temperature service. Properties of both based metal and welds were included in this study. The properties that were evaluated included tensile yield and ultimate strength, creep resistance, creep-rupture strength, impact behavior, fracture toughness,a and creep crack-growth behavior. Reasons for the observed changes in these mechanical properties and the importance of using the properties of service-aged materials in assessing structural integrity and remaining service life are discussed.
- OSTI ID:
- 131859
- Report Number(s):
- CONF-950740--; ISBN 0-7918-1334-7
- Country of Publication:
- United States
- Language:
- English
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