Autonomous Filling of Grain-Boundary Cavities during Creep Loading in Fe-Mo Alloys
- PDF / 3,339,543 Bytes
- 14 Pages / 593.972 x 792 pts Page_size
- 89 Downloads / 214 Views
NTRODUCTION
MOLYBDENUM is an important alloying element for high-performance steel grades to be deployed at elevated temperatures. It is mainly used to improve the creep properties by solid-solution strengthening.[1–3] For binary Fe-Mo alloys, several studies have been performed to determine the effect of the Mo concentration on the creep behavior at elevated temperatures,[4–7] but only limited data are available on the formation of Mo-containing precipitates in these model alloys.[8,9] In high-Cr steels containing Mo and/or W, the precipitation of the (Fe,Cr)2(Mo,W) Laves phase occurs during long-term exposure at higher temperatures. The influence of Mo on the creep properties has been interpreted exclusively in terms of solid-solution strengthening and precipitation hardening,[10,11] without considering its
S. ZHANG, Ph.D. Student, M.E. GRAMSMA, M.Sc. Student, E. BRU¨CK, Professor, and N.H. VAN DIJK, Researcher, are with the Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands. Contact e-mail: [email protected] H. FANG, Ph.D. Student, is with the Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, and also with the Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands. C. KWAKERNAAK, Research Assistant, and W.G. SLOOF, Researcher, are with the Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands. F.D. TICHELAAR, Researcher, is with the Kavli Institute of Nanoscience, National Centre for HREM, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands, M. KUZMINA, Ph.D. Student, M. HERBIG, Researcher, and D. RAABE, Professor, are with the MaxPlanck-Institut fu¨r Eisenforschung GmbH, Max-Planck-Straße 1, 40237, Du¨sseldorf, Germany. S. VAN DER ZWAAG, Professor, is with the Novel Aerospace Materials group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands. Manuscript submitted January 14, 2016. METALLURGICAL AND MATERIALS TRANSACTIONS A
role in mediating local creep damage in the form of grain boundary pores. Recently, Laha et al.[12–15] have reported that creep damage can be self-healed in compositionally modified austenitic stainless steels. They attributed the enhanced creep resistance to dynamic precipitation of Cu and BN at the crack surface, preventing further growth of the creep damage. In our previous work on Fe-Cu and Fe-Cu-B-N model alloys, Cu precipitation at deformation-induced structural defects was indeed found to take place.[16,17] However, the preference for Cu and BN to precipitate at open deformation-induced defects was found to be relatively weak and a high concentration of spherical Cu precipitates was formed homogeneously in the matrix, greatly reducing the healing potential of the Cu atoms initially brought
Data Loading...
