In this paper, the precipitation behavior and its effect on resistivity in a new type of nickel–iron-based alloy during short-term aging were investigated. During the aging process, the ${\mathsf{\gamma }}^{\prime }$ phase increases in average size and decreases in number, with its area fraction fluctuating over time. This fluctuation is caused by the mismatch in the redissolution and growth rates of the ${\mathsf{\gamma }}^{\prime }$ phase. As the area fraction of the ${\mathsf{\gamma }}^{\prime }$ phase increases, the content of solute atoms in the matrix that scatter electrons decreases, lowering the resistivity of the alloy. Additionally, the continuous precipitation of ${\mathrm{M}}_{23}{\mathrm{C}}_6$ at grain boundaries during aging causes the resistivity to gradually increase. This paper explains the fluctuation in the total amount of ${\mathsf{\gamma }}^{\prime }$ phase during short-term aging and proposes a new method for characterizing the precipitation behavior of the ${\mathsf{\gamma }}^{\prime }$ phase in the novel alloy using the relative trend of resistivity changes.

Electromagnetic induction heating, which converts electromagnetic energy into thermal energy via electron-lattice collisions, and heat conduction heating, which transfers thermal energy through lattice vibrations, both have significant impacts on the solid-state precipitation behavior caused by atomic diffusion. This paper proposes a creep method based on heat conduction heating, which utilizes the turning point of negative creep to measure the isothermal transformation start curve of the γ′ phase in the alloy. The results are compared with the thermal expansion experiments under electromagnetic induction heating and simulations from the thermodynamic analysis software JMatPro. The results indicate that the nucleation incubation period of the γ′ phase in the creep experiment is longer, excluding the non-thermal effects of electricity, and more consistent with actual heat treatment conditions. The overlapping precipitation of other phases, such as M₂₃C₆ carbides at grain boundaries, reduces the γ′ phase’s fastest precipitation temperature determined by the creep and thermal expansion methods, thereby lowering the accuracy of the isothermal transformation curve. This study provides a reference for optimizing production processes and evaluating the service performance of precipitation-strengthened iron–nickel-based alloys.