Effect of W on formation and properties of precipitates in Ni-based Superalloys
Zhi-hua Gong1,2, Yuan-yuan Ma1, Han-sheng Bao2, Gang Yang2
1 Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 2 Institute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China
Effect of W on formation and properties of precipitates in Ni-based Superalloys
Zhi-hua Gong1,2, Yuan-yuan Ma1, Han-sheng Bao2, Gang Yang2
1 Inner Mongolia University of Science and Technology, Baotou 014010, Inner Mongolia, China; 2 Institute for Special Steels, Central Iron and Steel Research Institute, Beijing 100081, China
摘要 The formation and properties of precipitates in wrought Ni-based superalloys with different W contents during long-term exposure to high temperatures were investigated. The scanning electron microscope, transmission electron microscope, and chemical phase analysis were used to investigate the formation and properties of precipitates. It is found that with increasing W content, the quantity and thermal stability of MC carbide in Ni-based superalloys increased, while the quantity of M23C6 carbides decreased. As the results show, W has a higher partition coefficient in c0- and c-matrix, and the addition of W promotes the precipitation of c0 phase. W content has no significant effect on the morphology, size, crystal structure, and coarsening rate of c0 precipitates. The influence of W content on high-temperature tensile and creep properties of the alloys was investigated. The results showed that W content has no obvious influence on the hightemperature yield strength, but the elongation and area reduction decreased significantly when the addition of W was more than 4 wt.%. Because of the similar volume fractions of c0 phase, the creep fracture strengths in the tested alloys with lower W concentrations were not significantly different after long-term exposure at 700 °C.
Abstract：The formation and properties of precipitates in wrought Ni-based superalloys with different W contents during long-term exposure to high temperatures were investigated. The scanning electron microscope, transmission electron microscope, and chemical phase analysis were used to investigate the formation and properties of precipitates. It is found that with increasing W content, the quantity and thermal stability of MC carbide in Ni-based superalloys increased, while the quantity of M23C6 carbides decreased. As the results show, W has a higher partition coefficient in c0- and c-matrix, and the addition of W promotes the precipitation of c0 phase. W content has no significant effect on the morphology, size, crystal structure, and coarsening rate of c0 precipitates. The influence of W content on high-temperature tensile and creep properties of the alloys was investigated. The results showed that W content has no obvious influence on the hightemperature yield strength, but the elongation and area reduction decreased significantly when the addition of W was more than 4 wt.%. Because of the similar volume fractions of c0 phase, the creep fracture strengths in the tested alloys with lower W concentrations were not significantly different after long-term exposure at 700 °C.
Zhi-hua Gong,Yuan-yuan Ma,Han-sheng Bao, et al. Effect of W on formation and properties of precipitates in Ni-based Superalloys[J]. Journal of Iron and Steel Research International, 2021, 28(7): 910-919.
2021, Vol. 28 
