Lei Penghui, Ji Xiaoyu, Chen Jiahao, Huang Yunhao, Lv Nan, Fan Yulin, Hou Yongchao, Shi Xinsheng, Yun Di
School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
State Key Laboratory of Advanced Nuclear Energy Technology, Nuclear Power Institute of China, Chengdu 610041, China.
Nanomaterials (Basel). 2025 Mar 7;15(6):413. doi: 10.3390/nano15060413.
To meet the application requirements for structural components in Gen-IV nuclear reactors, it is essential to improve the high-temperature mechanical properties of 25Ni-20Cr (S35140) austenitic stainless steel. In this research, an improved austenitic stainless steel (N-S35140), derived from S35140 steel, was investigated. The scanning transmission electron microscopy (STEM) results indicate that the addition of titanium (Ti) microalloying elements to S35140 steel led to the precipitation of new strengthening nano phases, including M(C, N), MC, MN and Ti(C, N), in N-S35140. These precipitates effectively compensated for the loss of high-temperature strength resulting from the substantial reduction in carbon content. During the in situ transmission electron microscopy (TEM) compressive process at room temperature, the yield strength of N-S35140 steel is 618.4 MPa. At room temperature, the tensile strength of N-S35140 steel is 638.5 MPa, with a yield strength of 392.8 MPa and an elongation of 32.7%, which surpasses those of S35140 steel at room temperature. N-S35140 steel exhibits a tensile strength of 330.6 MPa, a yield strength of 228.2 MPa, and an elongation of 51.4% during the in situ scanning electron microscopy (SEM) tensile test conducted at 650 °C. As a consequence, the improved N-S35140 steel demonstrates significantly enhanced mechanical properties compared to the original S35140 steel, positioning it as a promising candidate for structural components in Gen-IV nuclear reactors.
为满足第四代核反应堆结构部件的应用要求，提高25Ni-20Cr（S35140）奥氏体不锈钢的高温力学性能至关重要。在本研究中，对一种源自S35140钢的改进型奥氏体不锈钢（N-S35140）进行了研究。扫描透射电子显微镜（STEM）结果表明，在S35140钢中添加钛（Ti）微合金元素导致N-S35140中析出新的强化纳米相，包括M（C，N）、MC、MN和Ti（C，N）。这些析出物有效弥补了因碳含量大幅降低而导致的高温强度损失。在室温原位透射电子显微镜（TEM）压缩过程中，N-S35140钢的屈服强度为618.4MPa。室温下，N-S35140钢的抗拉强度为638.5MPa，屈服强度为392.8MPa，伸长率为32.7%，超过了室温下S35140钢的相应性能。在650℃进行的原位扫描电子显微镜（SEM）拉伸试验中，N-S35140钢的抗拉强度为330.6MPa，屈服强度为228.2MPa，伸长率为51.4%。因此，与原始的S35140钢相比，改进后的N-S35140钢具有显著增强的力学性能，使其成为第四代核反应堆结构部件的有前途的候选材料。
