Synthesis of atom probe experiments on irradiation-induced solute segregation in French ferritic pressure vessel steels |
| |
Authors: | P Auger P Pareige S Welzel J-C Van Duysen |
| |
Affiliation: | a Groupe de Physique des Matériaux, UMR CNRS 6634, Université-INSA de Rouen, 76821, Mont Saint Aignan, France b EDF, Centre de Recherche des Renardières, 77250, Moret sur Loing, France |
| |
Abstract: | Microstructural changes due to neutron irradiation cause an evolution of the mechanical properties of reactor pressure vessels (RPV) steels. This paper aims at identifying and characterising the microstructural changes which have been found to be responsible in part for the observed embrittlement. This intensive work relies principally on an atom probe (AP) study of a low Cu-level French RPV steel (Chooz A). This material has been irradiated in in-service conditions for 0–16 years in the frame of the surveillance program. Under this aging condition, solute clustering occurs (Cu, Ni, Mn, Si, P, …). In order to identify the role of copper, experiments were also carried out on Fe–Cu model alloys submitted to different types of irradiations (neutron, electron, ion). Cu-cluster nucleation appears to be directly related to the presence of displacement cascades during neutron (ion) irradiation. The operating basic physical process is not clearly identified yet. A recovery of the mechanical properties of the irradiated material can be achieved by annealing treatments (20 h at 450°C in the case of the RPV steel under study, following microhardness measurements). It has been shown that the corresponding microstructural evolution was a rapid dissolution of the high number density of irradiation-induced solute clusters and the precipitation of a very low number density of Cu-rich particles. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|