Assessment of neutron irradiation-induced grain boundary embrittlement by phosphorous segregation in a reactor pressure vessel steel

被引：0
作者：
Kimura, Akihiko [1 ]
Shibata, Masaaki [1 ]
Kasada, Ryuta [1 ]
Fujii, Katsuhiko [2 ]
Fukuya, Kohji [2 ]
Nakata, Hayato [2 ]
机构：
[1] Institute of Advanced Energy, Kyoto University, Gokasho, Uji
[2] Institute of Nuclear Safety System, Inc., Mihama, Mikata, Fukui 919-1205
来源：
Journal of ASTM International | 2005年 / 2卷 / 03期
关键词：
DBTT shift; Grain boundary fracture ratio; Non-hardening embrittlement; Phosphorous segregation;
D O I：
10.1520/JAI12398
中图分类号：
学科分类号：
摘要：
The materials used were two sorts of reactor pressure vessel steels (RPVSs), which contain different amounts of impurity phosphorous (P) and copper (Cu). The specimens for Charpy V-notch impact tests and Auger electron spectroscopy (AES) were irradiated in the Japan Materials Test Reactor (JMTR) at 290°C up to fluences of 6 × 1021 and 1 × 10 24 n/m2 using a multi-division temperature control capsule which enables removal of a part of the sub-capsules during operation of the reactor. Neutron irradiation resulted in a significant shift in the ductile-brittle transition temperature (DBTT) accompanied by a large irradiation hardening in the high P and high Cu steel. The AES measurements following the irradiations revealed that almost no phosphorous segregation occurred at grain boundaries. The DBTT shifts by neutron irradiation were reasonably interpreted in terms of a so-called hardening mechanism. The SEM observations of the fractured surface indicated that a very small amount of grain boundary fracture was induced at the irradiation conditions, and resultantly no grain boundary embrittlement was observed. Based on the results of irradiation experiments as well as long-term thermal aging experiments beyond 16 000 h, neutron irradiation-induced grain boundary embrittlement is considered to rarely happen to the RPVS that contains 110 wppm of phosphorous. Copyright © 2005 by ASTM International.
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页码：199 / 211
页数：12
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