Magnetic property of highly neutron-irradiated nuclear pressure vessel steels

对不同关键元素的反应堆压力容器钢进行了长期热老化试验，以阐明高注量区中子辐照脆化引起的磁性能变化机理。时效时间依赖性的结晶度，取决于时效温度和初始微观结构进行了观察。从这些结果中，可以得出结论，磁性能的变化可以是由于Cu沉淀物的形成，回复过程，和在基体中的晶格应变的松弛的综合作用，和主要原因是强烈依赖于初始微观结构的钢。

Long-term thermal aging experiments on reactor pressure vessel steels with variable key elements have been performed in order to elucidate mechanism of magnetic property changes due to neutron irradiation embrittlement in the high fluence regime. Aging time dependence of coercivity, depending on aging temperature and initial microstructure was observed. From these results, it was concluded that magnetic property changes can be due to a combined effect of the formation of Cu precipitates, recovery process, and relaxation of lattice strain in the matrix, and the major cause is strongly dependent on initial microstructure of the steels.