| Abstract Scope |
T91 steel aged for 50h, 100h, 300h, 500h, 850h and 1700h at 750℃ were analyzed by SEM, EDS, TEM and tensile tests to study on changing rules of microstructure and properties along with aging time. Results show that, with the increase of aging time, the count of precipitates corresponds with function: , the average size of precipitates corresponds with function: , the area fraction of precipitate phases corresponds with function: . With the extend of aging time, content of Cr and Mo in matrix decrease, the content of Cr and Mo in precipitate phases increase, there are Laves phase appear when aging for 850h, these means that Cr and Mo in matrix migrated to precipitate phases and alloy elements redistribution happened. As aging time went on, strength indexes and plasticity indexes present a decreasing tendency. |