Dynamic recrystallization mechanism of 15Cr25NiFe base superalloy
1.Key Laboratory for Mechanical Behavior and Microstructure of Materials of Guizhou Province, School of Materials and Metallurgy, Guizhou University, Guiyang, Guizhou 550003, China; 2.High Temperature Materials Research Institute, Central Iron & Steel Research Institute, Beijing 100081, China; 3.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
Abstract:15Cr25NiFe base alloy is a precipitation strengthening deforming superalloy, which is commonly used in heavyduty gas turbine. At the condition of strain temperature from 950 ℃ to 1 200 ℃ and strain rate from 0001 s-1 to 10.000 s-1, the hot compressing testings were completed with the Gleeble1 500 simulator. The apparent active energies of this superalloy were studied with the active energy model. With the optical microscope and TEM, the dynamic recrystallization mechanism was analyzed. The results show that the dynamic recrystallizations at the strain rate of 0010~0100 s-1 and temperature range of 1 050~1 200 ℃ are controlled by nucleation. The grains with uniform size are equiaxed and the grain boundaries are smooth. The grain size is uniform, and there are many subgrains.