Microstructures and Mechanical Properties of a Newly Developed Austenitic Heat Resistant Steel

作     者：Peng Liu Zhao-Kuang Chu Yong Yuan Dao-Hong Wang Chuan-Yong Cui Gui-Chen Hou Yi-Zhou Zhou Xiao-Feng Sun 

作者机构：Institute of Metal ResearchChinese Academy of Sciences School of Materials Science and EngineeringUniversity of Science and Technology of China Xi'an Thermal Power Research Institute Co.Ltd. Jiangsu Feiyue Pump Group Co.Ltd. 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2019年第32卷第4期

页      面：517-525页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported financially by the National Natural Science Foundation of China (Nos. 11332010,51671189 and 51701210) the Project from China Huaneng Group Co. Ltd. (No. ZD-15-HJK02) 

主　　题：Austenitic heat resistant steel Microstructure Mechanical property Fracture mode 

摘      要：The effect of heat treatment on the microstructures and mechanical properties of a newly developed austenitic heat resistant steel(named as T8 alloy) for ultra-supercritical applications have been studied. Results show that the main phases in the alloy after solution treatment are γ and primary MX. Subsequent aging treatment causes the precipitation of M_(23)C_6 carbides along the grain boundaries and a small number of nanoscale MX inside the grains. In addition, with increasing the aging temperature and time, the morphology of M_(23)C_6 carbides changes from semi-continuous chain to continuous *** with a commercial HR3C alloy, T8 alloy has comparable tensile strength, but higher stress rupture strength. The dominant cracking mechanism of the alloy during tensile test at room temperature is transgranular, while at high temperature, intergranular cracking becomes the main cracking mode, which may be caused by the precipitation of continuous M_(23)C_6 carbides along the grain boundaries. Typical intergranular cracking is the dominant cracking mode of the alloy at all stress rupture tests.