Effect of Long-term Aging on Microstructure and Mechanical Properties of 2205 Duplex Stainless Steel at 500°C

2018 3rd International Conference on Insulating Materials, Material Application and Electrical Engineering

材料科学;无线电电子学;电工学

Wang, Jiawei^1,2 ; Gong, Xiufang^1,2 ; Wang, Tianjian^1,2 ; Wang, Jun^3 ; Pan, Dong^4

Dongfang Electric Corporation Dongfang Turbine Co. LTD, Deyang

618000, China^1

State Key Laboratory of Long-Life High Temperature Materials, Deyang

618000, China^2

School of Material Science and Engineering

Sichuan University, Chengdou

610065, China^3

Nuceal Power Institute of China, Chengdou

610041, China^4

关键词: 2205 duplex stainless steel;    Ferrite phase;    Fractographs;    Fracture morphology;    Intragranular fractures;    Long-term aging;    Microstructure and mechanical properties;    Transmission electron micrograph;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/452/2/022065/pdf
DOI  :  10.1088/1757-899X/452/2/022065

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The microstructure and mechanical properties of 2205 duplex stainless steel (DSS) during long-term aging at 500°C were studied. The results showed the hardness of specimens increased all the time during aging, reach the peak with aged for 5800h. Besides, aging at 500°C led to a significant decrease in toughness and notable increase in strength. Fractographs showed that, with increasing aging time, the fracture morphology changed from fibrous fracture to Tran's granular and intragranular fracture. Finally, the changes in microstructure due to aging were studied by optical microscope, scanning electron microscopy and transmission electron microscopy. Transmission electron micrographs revealed that many dislocations and precipitates were distributed along α/γ and α/α interfaces. The precipitates were extracted and confirmed by diffraction pattern to be Cr2N and R-phase; they precipitate from the ferrite phase. Therefore, it can be concluded that dislocation, Cr2N and R-phase are the main reason for the egligible effects on mechanical properties in aged 2205 DSS. The mechanical properties are mainly influenced by the microstructure of ferrite.