Wang Jiaqi,Yao Zhiqiang,Wu Jinrong,et al.Effects of Ti Microalloying on the Microstructure and Mechanical Properties of a Novel GH1059 Alloy for Nuclear Applications[J].Special Steel,2025,46(04):84-91.
Wang Jiaqi,Yao Zhiqiang,Wu Jinrong,et al.Effects of Ti Microalloying on the Microstructure and Mechanical Properties of a Novel GH1059 Alloy for Nuclear Applications[J].Special Steel,2025,46(04):84-91. DOI: 10.20057/j.1003-8620.2025-00098.
Effects of Ti Microalloying on the Microstructure and Mechanical Properties of a Novel GH1059 Alloy for Nuclear Applications
The influence of Ti microalloying on the microstructure and mechanical properties of a novel Fe-Ni-based superalloy GH1059 with high-strength, high-toughness and long-life for fast reactors was investigated using SEM, EBSD, and TEM. The results showed that the addition of Ti significantly increased the amount of Ti-rich MC carbides, which precipitated in a finer and more dispersed manner, while effectively suppressing the formation of M
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carbides at grain boundaries (GBs). With increasing Ti content, the average grain size of the alloy gradually decreased, while the fraction of low-Σ coincidence site lattice (CSL) boundaries remained largely unchanged. The results of 750 ℃ tensile and room temperature impact properties showed that Ti microalloying can simultaneously improve both strength and toughness. The tensile fracture mode was a mixed-mode fracture, and the deformed microstructure was mainly composed of dislocation cells and sub-grains. The improvement in mechanical properties were primarily attributed to solid-solution strengthening by Ti atoms, precipitation strengthening from TiC, grain refinement, and enhanced GB bonding force.
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