Original Article

Precipitation and evolution of carbides in Fe-Cr-Al alloys under heat treatments

¹ School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, Liaoning, PR China
² Beijing Shougang Gitane New Materials Company Ltd, Beijing 102200, PR China
³ Key Laboratory of Metallurgy Engineering Liaoning Province, University of Science and Technology Liaoning, Anshan 114051, Liaoning, PR China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 5 December 2025
Accepted: 1 March 2026

Abstract

This study systematically investigates the precipitation and evolution behaviors of TiC, ZrC, and YC₂ carbides in FeCrAl alloys through heat treatments at 600, 900, and 1200 °C, combined with thermodynamic calculations, growth kinetics modeling, and dissolution simulations. The results show that the precipitation of the three carbides exhibits strong temperature dependence: TiC and ZrC are the dominant phases in the as-received alloy; after heat treatment at 600 and 900 °C, YC₂ becomes the main precipitated phase; at 1200 °C, TiC and ZrC re-precipitate extensively, forming fine TiC nanoparticles and irregular ZrC–YC₂ composite structures. Thermodynamic analysis indicates that all three carbides satisfy the liquid-phase precipitation conditions within the carbon range of 0.005–0.05 wt.%, among which YC₂ shows the strongest precipitation tendency. Competitive stability calculations reveal that TiC exhibits the highest thermodynamic stability at elevated temperatures, followed by ZrC, whereas YC₂ remains stable mainly at lower temperatures. Growth kinetics results show that carbide size increases with carbon content, with YC₂ exhibiting the largest growth, followed by TiC, while ZrC grows the least. According to the LSW theoretical prediction, the coarsening of the three carbides is minimal within 600–1200 °C, and the sizes of TiC and YC₂ remain nearly unchanged. Dissolution simulations further demonstrate a strong temperature sensitivity: at 1200 °C, the dissolution time of 5 μm carbides is significantly reduced, with TiC, ZrC, and YC₂ requiring 125.47, 233.47, and 229.40 s, respectively, whereas at 600 and 900 °C, the dissolution time increases sharply.