TY - JOUR
T1 - Intergranular segregation in the pressure vessel steel of a commercial nuclear reactor studied by atom probe tomography
AU - Toyama, Takeshi
AU - Nagai, Yasuyoshi
AU - Al Mazouzi, Abderrahim
AU - Hatakeyama, Masahiko
AU - Hasegawa, Masayuki
AU - Ohkubo, Tadakatsu
AU - van Walle, Eric
AU - Gérard, Robert
N1 - Acknowledgements
The authors would like to thank Dr. L. Malerba and Dr. Y.
Matsukawa for useful discussions, M. Narui and M.
Yamazaki for their support of hot laboratory work and the
Utility Electrabel for permission to publish the present results
on the surveillance test specimens. This work was partially
supported by Grants-in-Aid for Scientific Research of
the Ministry of Education, Culture, Sports, Science and
Technology, Japan (Nos. 17002009, 17760676, 18686077
and 23760822), a research program of the Japan Nuclear
Energy Safety Organization and Nuclear Research of
the Ministry of Education, Culture, Sports, Science and
Technology, based on screening and counseling by the
Atomic Energy Commission.
PY - 2013
Y1 - 2013
N2 - Solute/impurity segregation and precipitation at grain boundaries (GBs) in a nuclear reactor pressure vessel (RPV) steel were investigated using laser-assisted atom probe tomography (APT): RPV surveillance test specimens irradiated in a commercial nuclear reactor to neutron doses of 0.83 × 1019 n•cm2 (low-dose) and 5.1 × 1019 n•cm2 (high-dose), corresponding to in-service exposure of ∼5 and ∼30 years, respectively. The segregation of C, P and Mo was found on GBs after the low-dose irradiation. The segregation of Si and Mn as well as C, P and Mo was observed after the high-dose irradiation. The monolayer coverage of P is estimated to be less than a suggested level for intergranular embrittlement. The segregation of C, P and Mo was also observed along parallel array of dislocation lines in small-angle grain boundaries. However, no segregation of Si and Mn was detected there. Copper-nano precipitates (CNPs) were observed on the GBs, along the dislocation lines and in the matrix. The sizes and the solute-impurity enrichment in these CNPs are compared.
AB - Solute/impurity segregation and precipitation at grain boundaries (GBs) in a nuclear reactor pressure vessel (RPV) steel were investigated using laser-assisted atom probe tomography (APT): RPV surveillance test specimens irradiated in a commercial nuclear reactor to neutron doses of 0.83 × 1019 n•cm2 (low-dose) and 5.1 × 1019 n•cm2 (high-dose), corresponding to in-service exposure of ∼5 and ∼30 years, respectively. The segregation of C, P and Mo was found on GBs after the low-dose irradiation. The segregation of Si and Mn as well as C, P and Mo was observed after the high-dose irradiation. The monolayer coverage of P is estimated to be less than a suggested level for intergranular embrittlement. The segregation of C, P and Mo was also observed along parallel array of dislocation lines in small-angle grain boundaries. However, no segregation of Si and Mn was detected there. Copper-nano precipitates (CNPs) were observed on the GBs, along the dislocation lines and in the matrix. The sizes and the solute-impurity enrichment in these CNPs are compared.
KW - Atom probe tomography
KW - Grain boundary segregation
KW - Irradiation effect
KW - Reactor pressure vessel steel
UR - http://www.scopus.com/inward/record.url?scp=84887451844&partnerID=8YFLogxK
U2 - 10.2320/matertrans.M2013133
DO - 10.2320/matertrans.M2013133
M3 - Article
AN - SCOPUS:84887451844
SN - 1345-9678
VL - 54
SP - 2119
EP - 2124
JO - Materials Transactions
JF - Materials Transactions
IS - 11
ER -