热循环对奥氏体耐热钢组织和力学性能的影响  

Effect of thermal cycle on microstructure and mechanical properties of the austenitic heat resistant steel

作　　者：何阳 翟亚中 赵吉庆[2] 车洪艳 李激光[1] HE Yang;ZHAI Ya-zhong;ZHAO Ji-qing;CHE Hong-yan;LI Ji-guang(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China;Institute for Special Steels,Center Iron and Steel Research Institute Co.Ltd.,Beijing 100081,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051 [2]钢铁研究总院有限公司特殊钢研究院,北京100081

出　　处：《兰州理工大学学报》2025年第1期11-18,共8页Journal of Lanzhou University of Technology

基　　金：钢铁研究总院基金(22T61240)的资助

摘　　要：奥氏体耐热钢由于良好的高温性能因而在火电、核电、航空航天等领域有着重要的应用.细小的晶粒尺寸及基体中弥散分布的碳化物是奥氏体钢具有优异高温性能的关键.奥氏体钢在服役过程中受热循环的影响,其显微组织发生衰退.为探究热循环过程中组织演变对力学性能的影响,针对一种供货态的奥氏体耐热钢0Cr25Ni13Si2MoN开展了三组热循环实验.借助光镜(optical microscope,OM)、扫描电镜(scanning electron microscope,SEM)、透射电镜(transmission electron microscope,TEM)和冲击试验机等试验设备,对不同热循环次数后的试样分别进行了显微组织及力学性能分析.结果表明:热循环过程中的组织演变表现出一定的时间依赖性,一次热循环过程完成了回复与再结晶,晶界处析出网状分布的M 23 C 6,降低了材料的韧性.后两次的热循环过程退火孪晶密度增大,但晶界处碳化物数量增加并发生粗化,材料的韧性逐渐恶化.Austenitic heat resistant steels are widely used in thermal power,nuclear power,aerospace,and other fields owing to their excellent performance at high temperatures.Fine grain size and uniform distributed carbides within the matrix are important reasons for austenitic steels with excellent performance.The microstructure of austenitic steel would experience degradation under extreme working conditions accompanied by thermal cycles.To clarify the effect of microstructure evolution on mechanical properties during the thermal cycle process,three sets of thermal cycles were carried out on an austenitic heat resistant steel 0Cr25Ni13Si2MoN on the condition of delivery.Optical microscope(OM),scanning electron microscope(SEM),and transmission electron microscope(TEM)were used to analyze the microstructure of the materials that experienced thermal cycles after different times.Also,impact toughness tests were carried out,respectively.The results showed that there exists a relationship between the microstructure evolution and time during the thermal cycles,recovery and recrystallization happen to the steel accompanied with M 23 C 6 precipitated around grain boundaries during the first thermal cycle,which decreased the impact toughness,and the density of annealing twins is increased during the next two thermal cycles,however,the carbides is increased and coarsened,which increases the impact toughness.

关 键 词：奥氏体耐热钢 0Cr25Ni13Si2MoN钢 热循环 组织演变 冲击韧性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]