Effect of Ti Addition on Nonmetallic Inclusions in FeCrAl Alloys

To investigate the influence mechanisms of Ti addition on inclusions in FeCrAl alloys, a series of experiments and thermodynamic calculations are carried out by controlling Ti additions. In FeCrAl alloys without Ti, inclusions are mainly AlN, and a tiny amount of Al 2 O 3 is surrounded by AlN inclusions. In the sample containing 0.025 wt%Ti, AlN inclusions occupy a dominant position, and no TiN inclusions are detected; as the Ti content increases to 0.127 wt%, AlN inclusions are the main component and begin to transform into TiN, with single‐phase TiN and TiN‐AlN complex inclusions appearing; when the Ti content reaches 0.277 wt%, AlN inclusions completely disappear, while inclusions are mainly single‐phase TiN and Al 2 O 3 ‐TiN complex inclusions. The number density of AlN inclusions decreases with Ti addition, indicating that the addition of Ti inhibits the formation of AlN inclusions. Based on the Clyne‐Kurz model, a coupling model is established to calculate the precipitation behavior of AlN and TiN inclusions in FeCrAl alloys during solidification. The results show that the precipitation of AlN is completely inhibited when the Ti content reaches the critical threshold of 0.176 wt%. The experimental results are consistent with the calculation results of FactSage 8.0 and the coupling model.