Abstract

The mechanisms of degradation of the structure and properties of steels of pressure vessels of pressurized water reactors (PWRs) have been analyzed using еlectron backscatter diffraction (EBSD) method, whose possibilities are demonstrated by an example of materials of the pressure vessels of the VVER-440 reactors after 45 years of operation. It is shown that the long-term use of the materials of a VVER-440 pressure vessel at elevated operating temperatures (~270°C) induces the occurrence of portions with intercrystallite fracture, which was not observed previously. Fracture occurs at the boundaries of primary austenitic grains along the ferrite–bainite interface.

中文翻译：

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EBSD方法在操作因素下反应堆压力容器钢断裂机理研究中的应用

摘要

已经使用电子背散射衍射（EBSD）方法分析了压水堆（PWR）压力容器钢结构和性能退化的机制，其可能性通过 VVER 压力容器材料的一个例子来证明 -运行 45 年后的 440 座反应堆。结果表明，在升高的操作温度 (~270°C) 下长期使用 VVER-440 压力容器的材料会导致出现晶间断裂部分，这是以前未观察到的。断裂发生在沿铁素体-贝氏体界面的初生奥氏体晶粒边界处。