核反应堆压力容器模拟钢中富Cu原子团簇的析出与嵌入原子势计算

利用原子探针层析技术(APT)和热处理时效方法,研究了合金元素Ni对核反应堆压力容器模拟钢中富Cu原子团簇析出的影响.实验结果表明,添加合金元素Ni(0.84wt%)的样品中析出富Cu原子团簇的数量密度高于不添加Ni的样品,富Cu原子团簇内以及团簇和基体界面处都有Ni元素的富集现象,这说明合金元素Ni会促使富Cu原子团簇的析出.从多体势的角度出发,利用嵌入原子势理论,基于纯金属元素Fe,Cu,Ni的多体势参数,建立了Fe-Cu二元和Fe-Cu-Ni三元体系的嵌入原子多体势.计算结果表明,当模拟合金中存在1at%Ni时有利于富Cu原子团簇的析出,这与实验结果相符.

Precipitation of Cu-rich clusters in reactor pressure vessel model steels and embedded-atom method potentials

Atom probe tomography characterization and thermal aging method have been employed to investigate the precipitation of Cu-rich clusters in reactor pressure vessel (RPV) model steels with and without the addition of Ni alloying element.It is observed that the number density of Cu-rieh clusters in the PRV model steel with the addition of Ni (0.84 wt%) is higher than that without the addition of Ni.The segregation of nickel in the Cu-rich clusters and at the boundaries of clusters/matrix was also observed.It is found that the nickel alloying element can promote the precipitation of Cu-rich clusters in RPV model steel.An analytical embedded atom method model of Fe-Cu and Fe-Cu-Ni system is constructed on the basis of the physical properties of pure constituents Fe, Cu and Ni.The calculation results show that the nickel (1 at%) can promote the precipitation of Cu-rich clusters.The calculation results agree with the results of experiments.