Zhang Hong,Wang Yongqiang,Li Xu,et al.Effect of Residual Nb on Mechanical Properties of GH4080A Alloy[J].Special Steel,2026,47(01):22-27.DOI: 10.20057/j.1003-8620.N250501.
Effect of Residual Nb on Mechanical Properties of GH4080A Alloy
During industrial-scale smelting processes, the use of recycled materials/returns to reduce costs and enhance resource utilization efficiency, along with elemental residues from furnace lining materials, can introduce residual impurity elements into the alloy. This study investigates the influence of varying residual Nb contents generated during the smelting process on the mechanical properties of GH4080A alloy at both room temperature and 750 ℃.The results demonstrate that as the residual Nb content increases, Nb segregates at grain boundaries and clusters into coarse Nb-contain carbide bands. These clustered Nb-contain carbides exhibit no significant impact on room-temperature tensile properties but severely degrade the alloy's high-temperature stress rupture properties. When the residual
w
[Nb] content reaches 0.05%, the stress rupture life at 750 ℃ drops below 100 hours (as per specification requirement ≥100 hours).Consequently,
w
[Nb] content must be strictly controlled below 0.05% during GH4080A alloy smelting. This research elucidates the underlying mechani
sm through which residual Nb deteriorates the high-temperature stress rupture performance of GH4080A alloy and offers practical guidance for elemental control in its industrial-scale smelting.
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