1 Shanghai Institute of Special Equipment Inspection and Technical Research, Shanghai 200062, China 2 Capital Aerospace Machinery Corporation Limited, Beijing 100076, China 3 National Engineering Research Centre of Die & Mold CAD, Shanghai Jiao Tong University, Shanghai 200030, China
Creep rupture behavior and microstructural evolution of modified 9Cr–1Mo heat-resistant steel
1 Shanghai Institute of Special Equipment Inspection and Technical Research, Shanghai 200062, China 2 Capital Aerospace Machinery Corporation Limited, Beijing 100076, China 3 National Engineering Research Centre of Die & Mold CAD, Shanghai Jiao Tong University, Shanghai 200030, China
摘要 High-temperature creep rupture behavior of modified 9Cr–1Mo steel used for steam cooler was investigated at temperature of 838 and 923 K and stress ranging from 100 to 250 MPa. Based on the analysis of creep rate–time curves, it is found that the creep rupture life decreases with the increase in the applied stress and temperature. The creep damage tolerance factor has been identified as a value of 8. In the normalized and tempered condition, the studied steel shows typical martensitic microstructure with Cr-rich M23C6 and Nb- or V-rich MX precipitates. Moreover, the Laves phase has been found along the grain boundaries. The fracture morphology characterized by field emission scanning electron microscope is adopted to reveal the creep failure mechanisms. The investigated results indicate the occurrence of the transgranular fracture under all the creep test conditions.
Abstract：High-temperature creep rupture behavior of modified 9Cr–1Mo steel used for steam cooler was investigated at temperature of 838 and 923 K and stress ranging from 100 to 250 MPa. Based on the analysis of creep rate–time curves, it is found that the creep rupture life decreases with the increase in the applied stress and temperature. The creep damage tolerance factor has been identified as a value of 8. In the normalized and tempered condition, the studied steel shows typical martensitic microstructure with Cr-rich M23C6 and Nb- or V-rich MX precipitates. Moreover, the Laves phase has been found along the grain boundaries. The fracture morphology characterized by field emission scanning electron microscope is adopted to reveal the creep failure mechanisms. The investigated results indicate the occurrence of the transgranular fracture under all the creep test conditions.
REN Fa-Cai,FEI -Chen,TANG Xiao-Yang. Creep rupture behavior and microstructural evolution of modified 9Cr–1Mo heat-resistant steel[J]. Journal of Iron and Steel Research International, 2018, 25(12): 1303-1307.
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