Author:
Ma Yulin,Kuang Chengyang,Cheng Jun,Yang Changdi
Abstract
AbstractIn this study, the short-term aging was carried out to reveal the evolution of precipitates and mechanical properties of heat resistant 9CrMoCoB steel during the early creep, replacing the conventional creeping. The tempered martensite lath structure (TMLS) and precipitates were observed in the as-aged 9CrMoCoB steel. TMLS in the matrix underwent a transition to the polygonal ferrite after aging only for 300 h. In comparison, the mean diameter of the precipitates increased from 183 to 267 nm after aging at 650 °C for 300 h. Also, the mean diameter of the precipitates increased from 183 to 302 nm at 700 °C. The room-temperature and high-temperature strength of 9CrMoCoB steel decreased after high-temperature aging, which may be mainly due to precipitates coarsening. Many M23C6 phases precipitate in the prior austenite grain boundary (PAGB) and lath boundary. After aging 100 h, TMLS transformed into polygonal ferrite, and the size of the precipitate at the subgrain boundary was about 100 nm, while after 300 h of high-temperature aging, large precipitates appear (400 nm) in the matrix. After 200 h of high-temperature aging, the obvious growth of precipitates on the PAGB and lath boundary weakens the pinning effect on the PAGB and martensite lath boundary and accelerates the transformation of microstructure and mechanical properties.
Publisher
Springer Science and Business Media LLC
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science
Reference39 articles.
1. Y. Liu, Y. Ma, H. Guo and C. Liu, Effects of Co and B on Microstructure and Properties of Modified Ferritic Heat-resistant Steels, Materials Review, 2015, 13, p 003.
2. R. Viswanathan, J.F. Henry, J. Tanzosh, G. Stanko, J. Shingledecker, B. Vitalis and R. Purgert, U.S. Program on Materials Technology for Ultra-Supercritical Coal Power Plants, J. Mater. Eng. Perform., 2005, 14(3), p 281–292.
3. T.U. Kern, M. Staubli and B. Scarlin, The European Efforts in Material Development for 650 Degrees C USC Power Plants - COST522, ISIJ Int., 2002, 42(12), p 1515–1519. (in English)
4. C.H. Jia, C.X. Liu, Y.C. Liu, C. Li and H.J. Li, Microstructural Evolution and Constitutive Models of 9CrMoCoB Heat-Resistant Steel During High-Temperature Deformation, J. Iron Steel Res. Int., 2019, 26(11), p 1228.
5. S.T. Mandziej and A. Vyrostkova, Creep and Fracture Behavior of Long-Annealed Weld HAZ in CB2 Steel, Weld World, 2020, 64(3), p 573–590.
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