Homogenization behavior of IN 718 superalloy prepared by electron beam layered solidification technology

Abstract

Abstract The homogenization behavior of IN 718 superalloy prepared by electron beam layered solidification has been investigated at 1150 °C. The set temperature was accurately corrected as 1149 °C by a compound method. The effect of homogenization treatment on the microstructure and microsegregation evolution was discussed by two models. A further discussion about Nb diffusion was conducted. The results show that the microsegregation was eliminated after the ingot was homogenized for 8 h at 1150 °C. Meanwhile, DNb and DTi is calculated approximately as 3.8 × 10−11 cm2/s and 4.0 × 10−11 cm2/s, respectively. The completion time of homogenization at a certain temperature depends on the degree of segregation, the distance between the secondary dendrite arms and the content of Nb. Additionally, it seems like that the DNb in IN 718 alloy decreases with the decrease of its concentration at the same temperature.