Metallurgical and Materials Transactions A

, Volume 41, Issue 6, pp 1441–1447

Evolution of Carbide Precipitates in 2.25Cr-1Mo Steel during Long-Term Service in a Power Plant

Authors

    • Engineering Physics DepartmentUniversity of Wisconsin–Madison
  • Yiren Chen
    • Argonne National Laboratory
  • Kumar Sridharan
    • Engineering Physics DepartmentUniversity of Wisconsin–Madison
  • Todd R. Allen
    • Engineering Physics DepartmentUniversity of Wisconsin–Madison
Article

DOI: 10.1007/s11661-010-0194-6

Cite this article as:
Yang, Y., Chen, Y., Sridharan, K. et al. Metall and Mat Trans A (2010) 41: 1441. doi:10.1007/s11661-010-0194-6

Abstract

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 (537 °C). 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.

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2010