9Cr3W低活性马氏体钢微观组织及力学性能的初步研究

通过提高W含量，调整V、Ta、Ti、N等微合金元素含量，设计了9Cr3W型低活性马氏体钢。研究了该钢的微观组织结构与硬化、时效及相转变行为，对其进行了拉伸性能和冲击韧性测试。与Eurofer97钢相比，该钢表现出优良的高温拉伸性能。分析了9Cr3W钢用作超临界水堆堆芯内部件及包壳材料的可行性，其高温力学性能远优于Zr合金包壳材料;拉伸性能与T91钢相当，且韧脆转变温度低于T91钢，冲击吸收功上限高于T91钢，具有优良的冲击韧性;9Cr3W钢的高温瞬时强度低于奥氏体316不锈钢，成为制约其用于超临界水堆堆芯内部件及包壳的因素之一。

Preliminary Investigation on Microstructure and Mechanical Properties of 9Cr3W Low Activation Martensitic Steel

9Cr3W low activation martensitic steel was designed by adding more tungsten and adjusting microalloy elements such as V, Ta, Ti and N. The microstructure and hardening, aging and transformation behavior were investigated. Tensile and charpy impact tests were performed. 9Cr3W steel has greatly improved high temperature instantaneous strength compared with the existing low activation ferritic/martensitic steels such as Eurofer97. Feasibility of the steel was analysed for in-core component and fuel cladding application in supercritical water cooled reactor. 9Cr3W steel has advantages in tensile properties at elevated temperature relative to zircaloy and T91 steel and exhibits a lower ductile-brittle transition temperature and a higher upper shelf energy than T91 steel, indicating a superior impact toughness. However, instantaneous strength of 9Cr3W steel at elevated temperature is not high as AL316 austenite stainless steel for the use of in-core component and fuel cladding application in supercritical water cooled reactor.