Evolution of carbide precipitates in 2.25Cr-1Mo steel during long-term service in a power plant.

Journal Article · Tue Jun 01 04:00:00 EDT 2010 · Metall. Mater. Trans. A

DOI:https://doi.org/10.1007/s11661-010-0194-6· OSTI ID:982672

Yang, Y; Chen, Y; Sridharan, K; Allen, T R

Carbide precipitation from the steel matrix during long-term high-temperature exposure can adversely affect the fracture toughness and high-temperature creep resistance of materials with implications on the performance of power plant components. In the present work, carbide evolution in 2.25Cr-1Mo steel after long-term aging during service was investigated. Boiler pipe samples of this steel were removed from a supercritical water-cooled coal-fired power plant after service times of 17 and 28 years and a mean operational temperature of 810 K (537C). The carbide precipitation and coarsening effects were studied using the carbon extraction replica technique followed by analysis using transmission electron microscopy and energy dispersive X-ray spectroscopy. The carbides extracted using an electrolytic technique were also analyzed using X-ray diffraction to evaluate phase transformations of the carbides during long-term service. Small ball punch and Vickers hardness were used to evaluate the changes in mechanical performance after long-term aging during service.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 982672
• Report Number(s): ANL/NE/JA-66164
• Journal Information: Metall. Mater. Trans. A, Journal Name: Metall. Mater. Trans. A Journal Issue: 6 ; Jun. 2010 Vol. 41A; ISSN 1073-5623
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
AGING
BOILERS
CARBIDES
CARBON
EXTRACTION
FRACTURE PROPERTIES
MATERIALS
PERFORMANCE
PHASE TRANSFORMATIONS
PIPES
POWER PLANTS
PRECIPITATION
REPLICA TECHNIQUES
STEELS
TEMPERATURE RANGE 0400-1000 K
TRANSMISSION ELECTRON MICROSCOPY
VICKERS HARDNESS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY