The Charpy Impact Properties of Oxide Dispersion-Strengthened FeCrAl Alloys with Different Cr Contents

Oxide dispersion-strengthened FeCrAl alloys with different Cr contents of 5, 9 and 16 wt.% (hereinafter referred to as 5CrAlZr, 9CrAlZr and 16CrAlZr) were fabricated through mechanical alloying and hot isostatic pressing. The effect of Cr content on the microstructure and impact properties was investigated. The average grain size increased a little with the increase of Cr content. Both fine Y-Zr-O particles and Y-Al-O particles were found in all samples, while the ratio of Y-Al-O particles increased along with the increase of Cr content. The number density of nanoparticles in ODS FeCrAl alloys first slightly decreased and then increased along with the increase of Cr content. The Charpy impact toughness was measured and compared. 5CrAlZr shows the highest impact toughness. The DBTT (ductile–brittle transition temperature) of 5CrAlZr is only −82 °C. This value is much lower than those of 9CrAlZr and 16CrAlZr, which are −17 and −3 °C, respectively.