Abstract
In this paper, a method of using the second phase to control the grain growth in Fe–Al–Cr alloys was proposed, in order to obtain better mechanical properties. In Fe–Al–Cr alloys, austenitic transformation occurs by adding austenitizing elements, leading to the formation of the second phase and segregation at the grain boundaries, which hinders grain growth. FeCr(σ) phase was obtained in the Fe–Al–Cr alloys, which had grains of several microns and was coherent and coplanar with the matrix (Fe2AlCr). The nucleation of σ phase in Fe–Al–Cr alloy was controlled by the ratio of nickel to chromium. When the Ni/Cr (eq) ratio of alloys was more than 0.19, σ phase could nucleate in Fe–Al–Cr alloy. The relationship between austenitizing and nucleation of FeCr(σ) phase was given by thermodynamic calculation.
Highlights
Heat-resistant ferritic steels have better heat capacity and a lower thermal expansion rate than nickel-based alloys
Depending on the protective thermal growth oxides (TGO) to prolong the service life of alloys under harsh working conditions and maintain the stability of material systems and isolate pollutants, many researchers have proposed that Fe–Al–Cr alloys can be regarded as a new generation of nuclear fuel cladding materials [1,2]
Researchers generally intend to use the second phase in Fe–Al–Cr alloys to refine the grains and strengthen the matrix
Summary
Heat-resistant ferritic steels have better heat capacity and a lower thermal expansion rate than nickel-based alloys. Researchers generally intend to use the second phase in Fe–Al–Cr alloys to refine the grains and strengthen the matrix. Have suggested that the high temperature strength of nickel-based superalloys is attributed to the dispersion strengthening of Ni3Al. Similar microstructures could be obtained in the Fe–Al–Ni–Cr system with B2 ordered (Ni, Fe) Al precipitates in the ferritic matrix superalloys. In the Fe–Cr–Al ternary system, there is a miscible zone between the disordered A2 phase and the ordered B2 phase [6] These two phases have similar lattice parameters, and they are coherent and coplanar, which is a characteristic shared by alloys consisting of miscible phases and nickel-based superalloys. The aim of this study was to limit the grain growth of Fe–Al–Cr alloys by searching for a continuous and inhomogeneous micron-sized second phase in order to achieve good mechanical properties. As a common second phase in nickel-based superalloys, we tried to study its effects on iron-based superalloys
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
