TY - JOUR
T1 - In-situ SEM study of crack initiation and propagation behavior in a dissimilar metal welded joint
AU - Wang, W.
AU - Liu, T. G.
AU - Cao, X. Y.
AU - Lu, Y. H.
AU - Shoji, T.
N1 - Funding Information:
The work described in this paper was supported by the National Key Research and Development Plan (Grant number 2016YFF0203804 ); Fundamental Research Funds for the Central Universities (No. FRF-TP-16-041A1 ).
Publisher Copyright:
© 2018
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/6/27
Y1 - 2018/6/27
N2 - In this paper, the in-situ fracture tests were carried out to study the fracture mechanism of different regions (base region, weld region and interface region) in a dissimilar metal welded joint of nuclear power plant. The local microstructural effect on short crack initiation and propagation behavior was investigated. The results indicated that the mechanism of crack initiation and propagation was strongly depended on the microstructures of the difference zone in the dissimilar metal welded joint. There were large numbers of twins in the base region, and the cracks tended to initiate along the twin boundary. The base region exhibited the characteristics of ductile fracture. There was no twin existed in the weld metal. The crack tended to initiate at the slip band and propagate along the columnar grain boundary due to existence of the second phase particles along the grain boundary. The fracture mode of the weld metal was intergranular. In the interface region, the crack tended to propagate from the weld zone to the epitaxial zone, and then along the grain boundary of the epitaxial zone. The fracture mode was the combination of the brittle and ductile fracture. Meanwhile, the weld region has a lower resistance of crack initiation and propagation compared with the base region and interface region.
AB - In this paper, the in-situ fracture tests were carried out to study the fracture mechanism of different regions (base region, weld region and interface region) in a dissimilar metal welded joint of nuclear power plant. The local microstructural effect on short crack initiation and propagation behavior was investigated. The results indicated that the mechanism of crack initiation and propagation was strongly depended on the microstructures of the difference zone in the dissimilar metal welded joint. There were large numbers of twins in the base region, and the cracks tended to initiate along the twin boundary. The base region exhibited the characteristics of ductile fracture. There was no twin existed in the weld metal. The crack tended to initiate at the slip band and propagate along the columnar grain boundary due to existence of the second phase particles along the grain boundary. The fracture mode of the weld metal was intergranular. In the interface region, the crack tended to propagate from the weld zone to the epitaxial zone, and then along the grain boundary of the epitaxial zone. The fracture mode was the combination of the brittle and ductile fracture. Meanwhile, the weld region has a lower resistance of crack initiation and propagation compared with the base region and interface region.
KW - Dissimilar metal welded joint
KW - Electron back-scatter diffraction
KW - In-situ tensile test
KW - Schmid factor
UR - http://www.scopus.com/inward/record.url?scp=85047611752&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85047611752&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2018.05.077
DO - 10.1016/j.msea.2018.05.077
M3 - Article
AN - SCOPUS:85047611752
VL - 729
SP - 331
EP - 339
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
ER -