Liu Junkai, Liu Wenbo, Hao Zhe, Shi Tiantian, Kang Long, Cui Zhexin, Yun Di
Department of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
Materials (Basel). 2020 Feb 21;13(4):972. doi: 10.3390/ma13040972.
Two kinds of experimental ferritic/martensitic steels (HT-9) with different Si contents were designed for the fourth-generation advanced nuclear reactor cladding material. The effects of Si content and tempering temperature on microstructural evolution and mechanical properties of these HT-9 steel were studied. The microstructure of experimental steels after quenching and tempering were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM); the mechanical properties were investigated by means of tensile test, Charpy impact test, and hardness test. The microscopic mechanism of how the microstructural evolution influences mechanical properties was also discussed. Both XRD and TEM results showed that no residual austenite was detected after heat treatment. The results of mechanical tests showed that the yield strength, tensile strength, and plasticity of the experimental steels with 0.42% (% in mass) Si are higher than that with 0.19% Si, whereas hardness and toughness did not change much; when tempered at 760 °C, the strength and hardness of the experimental steels decreased slightly compared with those tempered at 710 °C, whereas plasticity and toughness increased. Further analysis showed that after quenching at 1050 °C for 1 h and tempering at 760 °C for 1.5 h, the comprehensive mechanical properties of the 0.42% Si experimental steel are the best compared with other experimental steels.
针对第四代先进核反应堆包壳材料，设计了两种不同硅含量的实验性铁素体/马氏体钢（HT-9）。研究了硅含量和回火温度对这些HT-9钢微观组织演变及力学性能的影响。通过X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对实验钢淬火和回火后的微观组织进行了表征；通过拉伸试验、夏比冲击试验和硬度试验研究了力学性能。还讨论了微观组织演变影响力学性能的微观机制。XRD和TEM结果均表明，热处理后未检测到残余奥氏体。力学试验结果表明，硅质量分数为0.42%的实验钢的屈服强度、抗拉强度和塑性高于硅质量分数为0.19%的实验钢，而硬度和韧性变化不大；在760℃回火时，实验钢的强度和硬度与在710℃回火时相比略有下降，而塑性和韧性有所提高。进一步分析表明，在1050℃淬火1 h并在760℃回火1.5 h后，0.42%硅实验钢的综合力学性能优于其他实验钢。
