Effects of neutron-irradiation-induced intergranular phosphorus segregation and hardening on embrittlement in reactor pressure vessel steels
Effects of neutron-irradiation-induced intergranular phosphorus segregation and hardening on embrittlement in reactor pressure vessel steels
复制标题
DOI：
10.1016/j.actamat.2008.05.026
复制
发表时间：
2008-09
期刊：
影响因子：
9.4
通讯作者：
Y. Nishiyama;K. Onizawa;Masahide Suzuki;J. Anderegg;Y. Nagai;T. Toyama;M. Hasegawa;J. Kameda
中科院分区：
文献类型：
--
作者：
Y. Nishiyama;K. Onizawa;Masahide Suzuki;J. Anderegg;Y. Nagai;T. Toyama;M. Hasegawa;J. Kameda
用扫描俄歇微区、局域电极原子探针和正电子湮没谱研究了不同磷、铜含量的几种中子辐照反应堆压力容器钢的晶间磷偏聚和硬化对韧脆转变温度（DBTT）的影响。在563K下增加中子注量能促进P在晶间的偏聚，特别是在高P含量的钢中。P含量（<570ppm）比Cu含量（<0.17wt.%）对辐照硬化的影响更显著。这是由于空位的稳定化引起的富P沉淀物的明显形成。分析了P偏析、硬化、沿晶断裂分数与DBTT之间的相关性，发现中子辐照减轻了P偏析的脆化效应，因此硬化对DBTT漂移的影响比P偏析更大，但高剂量辐照的高掺P钢除外。
The effects of intergranular P segregation and hardening on the ductile-to-brittle transition temperature (DBTT) in several neutron-irradiated reactor pressure vessel steels with different bulk contents of P and Cu have been investigated using a scanning Auger microbe, a local electrode atom probe and positron annihilation spectroscopy. Increasing the neutron fluence at 563K promotes intergranular P segregation, particularly in steels with high levels of P. The content of P (<570ppm) more significantly affects irradiation-hardening than that of Cu (<0.17wt.%) due to distinct formation of P-rich precipitates arising from the stabilization of vacancies. Analyzing the correlations between P segregation, hardening, fraction of intergranular fracture and DBTT, it is found neutron irradiation mitigates the embrittling effect of segregated P, and therefore the hardening more strongly affects the DBTT shift than the P segregation, with the exception of highly P-doped steel irradiated to high neutron fluence.