氮和铝添加对改进型25Ni-20Cr奥氏体不锈钢700℃时效处理后显微组织和力学性能的影响  

Effect of N and Al Addition on Microstructure and Mechanical Properties of Modified 25Ni-20Cr Austenitic Stainless Steel Aged at 700℃

作　　者：王琦 陈国帅 周张健[1] 熊茹[2] 郑继云 唐睿[2] 张乐福[3] Wang Qi;Chen Guoshuai;Zhou Zhangjian;Xiong Ru;Zheng Jiyun;Tang Rui;Zhang Lefu(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing,100083,China;Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中国核动力研究设计院反应堆燃料及材料重点实验室,成都610213 [3]上海交通大学核能科学与工程学院,上海200240

出　　处：《核动力工程》2023年第5期275-283,共9页Nuclear Power Engineering

基　　金：国家重点研发计划项目(2018YFE0116200);国家自然科学基金(51001299)。

摘　　要：为提高25Ni-20Cr(S35140)奥氏体不锈钢的高温强度,以满足超临界水堆(SCWR)对包壳材料的应用要求。采用微合金化方法,通过添加N和Al元素,并在700℃高温时效对S35140钢的性能进行改进。结果表明,加N钢中析出纳米级NbN相,钉扎位错,随时效进行,室温拉伸强度略有提高,室温延伸率几乎不变,高温拉伸强度略有降低,而高温延伸率提升至65%,时效120 h后冲击功仍然达到111.39 J;加Al钢中析出大量NiAl相和Laves相,随时效进行,室温和高温拉伸强度均显著提升,室温拉伸强度甚至达到1000 MPa,而塑性和冲击韧性下降明显。因此在S35140钢中,加N提高了塑韧性,加Al提高了强度,均显著改善S35140钢的力学性能。The high temperature strength of the 25Ni-20Cr(S35140) austenitic stainless steel needs to be improved to meet the application requirements of supercritical water reactor(SCWR)for cladding materials.In this study,the properties of S35140 Steel were improved by microalloying,adding N and Al and aging at 700℃.The results showed that nano-NbN phase precipitated in N-added steel,and dislocation was pinched.With aging,the tensile strength at room temperature increased slightly,the elongation at room temperature almost remained unchanged,and the tensile strength at high temperature decreased slightly;however,the elongation at high temperature increased to 65%,and the impact energy still reached 111.39 J after aging for 120 h.A large number of NiAl and Laves phases precipitated in Al-added steel.With aging,the tensile strength at room temperature and high temperature increased significantly,and the tensile strength at room temperature even reached 1000 MPa,while the ductility and impact toughness decreased significantly.Therefore,in S35140 steel,adding N increased the ductility and toughness,while adding Al increased the strength,both of which significantly improved the mechanical properties of S35140 steel.

关 键 词：S35140奥氏体钢 显微组织 力学性能 高温时效 

分 类 号：TL334[核科学技术—核技术及应用]