Journal of Shanghai University(Natural Science Edition) ›› 2013, Vol. 19 ›› Issue (1): 54-60.doi: 10.3969/j.issn.1007-2861.2013.01.011

• Material Science • Previous Articles     Next Articles

Element Segregation of Carbide/Matrix Interface in RPV Model Steel after Thermal Aging

JIA Xiang-nan, WANG Jun-an, CAI Lin-ling, XU Gang, WANG Xiao-jiao, LIU Wen-qing, ZHOU Bang-xin   

  1. 1. Laboratory for Microstructures, Shanghai University, Shanghai 200444, China;
    2. Institute of Materials, Shanghai University, Shanghai 200072, China
  • Received:2012-04-09 Online:2013-02-28 Published:2013-02-28

Abstract: Element segregation in thermal aged nuclear reactor pressure vessel (RPV) model steels with different amount of phosphorus was investigated by atom probe tomography (APT) analysis. After the initial heart treatment at 880 ºC-0.5 h and water quenching, the specimens were aged at 400 ºC for up to 500 h. The results show that phosphorus segregated to the carbide/matrix interface in both lower and higher phosphorus-containing specimens. A precipitate of phosphorus, silicon and carbon, with a thickness of about 20 nm, formed in the higher phosphoruscontaining specimens aged for 150 h. By extending aging time, phosphorus and silicon segregated and formed a thin layer at the boundaries of Fe3C. Silicon segregation suppressed the growth of Fe3C.

Key words: atom probe tomography (APT), element segregation, thermal aging, reactor pressure vessel (RPV) model steel

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