Microstructure and Properties Characteristics of Ni–25Cr–10Fe–xSi (x = 1, 2, 3, 4) Alloys for Waste Incineration Equipment.

The long-term aging behavior and corrosion resistance of Ni–25Cr–10Fe–xSi (x = 1, 2, 3, 4) alloys with varying Si content were systematically investigated. Ni–25Cr–10Fe–xSi alloys exhibited satisfactory mechanical properties even after aging at 650 °C for 5000 hours. The yield strength of the alloys exceeded 237 MPa, and the elongation exceeded 45.9 pct. No detrimental phases such as the η and σ phases precipitated during the long-term aging process, but Si segregation at grain boundaries in the form of carbides was observed. These carbides, while present, did not significantly affect the overall mechanical performance of the alloys. Meanwhile, the corrosion resistance of Ni–25Cr–10Fe–xSi alloys under the KCl–ZnCl₂ deposit increased with the increase in Si content. The higher Si content promoted the formation of a protective corrosion scale rich in Cr and Si, which acted as a barrier, preventing the penetration of oxygen and molten salt into the substrate. Ni–25Cr–10Fe–xSi alloys are expected to be suitable materials for waste incineration equipment. [ABSTRACT FROM AUTHOR]