High-temperature creep rupture behavior of modified 9Cr-lMo 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 ...High-temperature creep rupture behavior of modified 9Cr-lMo 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.展开更多
基金National Natural Science Foundation of China (Grant No.51705316)Shanghai Municipal Bureau of Quality and Technical Supervision (No.2016-40).
文摘High-temperature creep rupture behavior of modified 9Cr-lMo 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.
