Title: Effect of liquid metal embrittlement on low cycle fatigue properties and fatigue crack propagation behavior of a modified 9Cr-1Mo ferritic-martensitic steel in an oxygen-controlled lead-bismuth eutectic environment at 350 °C
Authors: Gong, Xing ×
Marmy, Pierre
Qin, Ling
Verlinden, Bert
Wevers, Martine
Seefeldt, Marc #
Issue Date: 2014
Publisher: Elsevier Sequoia
Series Title: Materials Science and Engineering A, Structural Materials: Properties, Microstructure and Processing vol:618 pages:406-415
Abstract: The low cycle fatigue properties of a modified 9Cr–1Mo ferritic–martensitic steel (T91) have been tested
in stagnant liquid lead–bismuth eutectic (LBE) with oxygen concentrations ranging from 1.16 106 to 6.0 1010 wt% at 350 1C. The effect of liquid metal embrittlement (LME) on fatigue endurance, fatigue crack propagation modes and secondary cracking has been studied. The results showed that the fatigue lives of T91 steel in a low oxygen concentration LBE were drastically reduced compared to those in vacuum due to the presence of LME. The microstructural observations on the fatigue crack propagation modes revealed that fatigue cracks in LBE mainly propagate across prior-austenite grain boundaries and then cut through martensitic lath boundaries, simultaneously leaving a few plastic flow traces and characteristic brittle features. Intergranular and interlath cracking occurred occasionally and their occurrence depended on the orientation of the boundaries relative to the stress axis. The complexity of the LME-induced fracture features can be attributed to a mixture of the multiple failure modes. No obvious plastic shear strain localization was present around the crack tips when LME occurred. However,
using a high resolution electron backscatter diffraction (EBSD) technique, highly localized plastic shear strain was observed in the vicinity of the crack tips in vacuum, manifested by the presence of very fine subgrains along the crack walls. A qualitative mechanism was proposed to account for the LME phenomenon in the T91/LBE system. In addition, the secondary cracking at fatigue striations was different in the presence of LBE compared to vacuum. This phenomenon was elucidated by taking into account the influence of the LME on the fatigue crack propagation rate.
ISSN: 0921-5093
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Structural Composites and Alloys, Integrity and Nondestructive Testing
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
pub07327.pdfMain article Published 5002KbAdobe PDFView/Open Request a copy

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science