研究不同磷含量的反应堆压力容器(reactor pressure vessel, RPV)模拟钢在880 ºC固溶, 400 ºC不同时间时效后碳化物周围元素的偏聚. 结果表明, 低磷和高磷模拟钢在时效过程中均发现板条内碳化物与基体界面处存在磷偏聚, 偏聚程度与晶界一致. 高磷样品时效150 h, P, Si和C同时在厚度约为20 nm的范围内富集, 其浓度为基体的2倍; 高磷样品时效500 h, 在Fe3C与基体的界面处分别存在厚度为7 nm的P和Si偏聚层, 其中P偏聚在近Fe3C一侧, Si偏聚在近基体一侧, Si的偏聚阻碍了碳化物的长大.
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.
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