Crystal Structure Evolution of the Cu-rich Nano Precipitates from bcc to 9R in Reactor Pressure Vessel Model Steel  

作　　者：Liu FENG Bangxin ZHOU Jianchao PENG Junan WANG 

机构地区：[1]Institute of Materials,Shanghai University [2]Analysis and Testing Center,Shandong University of Technology [3]Laboratory for Microstructures,Shanghai University

出　　处：《Acta Metallurgica Sinica(English Letters)》2013年第6期707-712,共6页金属学报（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2011CB610503);National Natural Science Foundation of China(No.50931003);Ministry of Major Subject of Shanghai(No.S30107)

摘　　要：The crystal structure evolution of the Cu-rich nano precipitates from bcc to 9R during thermal aging was studied in nuclear reactor pressure vessel （RPV） model steels. The specimens, contained higher copper and nickel contents than commercially available one, were heated at 890 ~C for 0.5 h and then water quenched followed by tempering at 0（50 ~C for I0 h and aging at 400 ~C for 1000 h. It was observed that bcc and 9R orthogonal structure, as well as 9R orthogonal and 9R monoclinic structure, coexist in a single Cu-rich nano precipitate. Further analyses pointed out that Cu-rich nano precipitates of bcc structure were not stable, it may preferentially transform to 9R orthogonal structure and then to 9R monoclinic structure. This results showed that the crystal structure evolution of the Cu-rich nano precipitates was complex.The crystal structure evolution of the Cu-rich nano precipitates from bcc to 9R during thermal aging was studied in nuclear reactor pressure vessel （RPV） model steels. The specimens, contained higher copper and nickel contents than commercially available one, were heated at 890 ~C for 0.5 h and then water quenched followed by tempering at 0（50 ~C for I0 h and aging at 400 ~C for 1000 h. It was observed that bcc and 9R orthogonal structure, as well as 9R orthogonal and 9R monoclinic structure, coexist in a single Cu-rich nano precipitate. Further analyses pointed out that Cu-rich nano precipitates of bcc structure were not stable, it may preferentially transform to 9R orthogonal structure and then to 9R monoclinic structure. This results showed that the crystal structure evolution of the Cu-rich nano precipitates was complex.

关 键 词：Reactor pressure vessel model steel Thermal aging Cu-rich nano precip-itates Structure evolution HRTEM 

分 类 号：TL351.6[核科学技术—核技术及应用]