Transformation of Chemical and Phase Composition in Al/FeAl₃(Cr,Ni)/Fe₂Al₅(Cr,Ni) Laminated Coating at High Temperature Heating

Abstract

The effect of thermal action at 1100 °C on the kinetics of phase transformations in the coating, obtained by hot-dip aluminizing of 12Cr18Ni10Ti steel, is studied. It was shown that, after 500 h of exposure, the chemical composition is leveled over the entire volume of the sample. Moreover, the predicted retention time of the heat-resistant properties of the coating at 1100 °C is about 2000 h.

Aluminizing of the EP33 alloy by hot-dipping

“…The layer at the boundary with the substrate corresponds to the FeAl3 intermetallic compound with Cr and Ni dissolved in it (table 3, point 3). At the same time, the formation of the Fe2Al5 phase was not observed in the coating, the formation of which is typical during aluminizing of Fe-based alloys [7,18]. 2) made it possible to identify Al phase and Cr2Al13 and FeAl3 intermetallic phases, which confirms the conclusions made on the basis of EDS analysis.…”

“…The layered coating structure formed on the EP33 alloy is similar to the data obtained during heat treatment of aluminized steel 12Cr18Ni10Ti [18]. The observed jump in the components concentration is due to a change in the solubility of Ni and other alloying components in the β phase as the temperature decreases, which leads to the formation of Ni-rich inclusions of the γ phase.…”

“…Works [13][14][15][16][17][18] investigated the influence of individual alloying components on the structure, phase and chemical composition of Al-containing coatings applied to Fe-based alloys. High temperature strength iron-based alloys usually contain a large number of alloying components, which complicates the task of alloy aluminizing due to the complex interaction of the components with aluminum.…”