Influence of Annealing Temperature on Microstructure and Mechanical Properties of Oxide Dispersion Strengthened‐FeCrAl Tube

The ferrite grain size, oxide nanoparticle, hardness, and tensile strength of cold‐rolled oxide dispersion strengthened (ODS)‐FeCrAl tube after annealing from 1100 to 1300 °C are investigated in detail. The results reveal that dislocation density decreased and average oxide nanoparticle size gradually increased with increasing annealing temperature. Grain orientation is not changed and type of oxide nanoparticle (Y 4 Zr 3 O 12 ) is not sensitive to annealing temperature. The average ferrite grain size increased and then decreased as a result of recrystallization at 1200 °C. The decrease in dislocation density led to a decrease in microvickers hardness from ≈305HV 0.2 to ≈266 HV 0.2 . After annealing at 1100 °C for 1 h, the ultimate tensile strength (UTS), yield strength (YS), and total elongation (TE) of annealed tube are ≈829 MPa, ≈677 MPa, and ≈17.9%, respectively. In this case, the contribution of precipitation strengthening and dislocation strengthening to YS decreased, which resulted in an increase in tensile ductility and a decrease in tensile strength after annealing. This article hopefully provides a reference for production of ODS‐FeCrAl tube with excellent strength‐ductility synergy via tailoring annealing.