Grain boundary character distribution of Hastelloy C276 modified by thermo-mechanical processing

Hastelloy C276 is a face-centered cubic metal material with low stacking fault energy, which is suitable for grain boundary engineering. It is possible to further improve its intergranular corrosion resistance by controlling the grain boundary network structure. Based on the concept of grain boundary engineering, this paper studies the procedure of thermo-mechanical processing (TMP) to control the grain boundary characteristic distribution of Hastelloy C276. The results show that after 3%-7% cold rolling and 1150℃ holding for 10min, the proportion of low-Σ CSL grain boundaries in the C276 alloy reaches more than 70%. The Σ3 boundaries (twin boundaries) occupy most of the CSL boundaries, resulting in the formation of large grain-clusters which are composed of grains with mutual Σ3ⁿ orientation relationship. The average grain cluster size reaches more than 110 μm, and a good grain boundary engineering treatment effect is obtained.