Microstructure and texture study on an advanced heat-resistant alloy during creep

In the present work, creep deformation and fracture behaviours of Sanicro 25 alloy were obtained based on long-term creep-strain tests. The multiscale precipitation behaviours were calculated thermodynamically and inspected by examination of the microstructure of the as-crept alloy. Creep cavitation nucleation near the M23C6 precipitates and an increase in amount of Laves phase with increased creep time were observed. The nanoscale MX-type and Cu-rich phases were found distributed evenly within the as-crept alloy, which leads to the high creep resistance of Sanicro 25 at elevated temperatures. The dislocation substructure evolution was surveyed, and dislocation cells were discovered in abundance of the alloy during creep. The grain orientation transformation of the alloy before and after creep were analysed, and 〈111〉//RD and 〈001〉//RD were detected as the preferred orientations during creep. The number of low-misorientation angles grain boundaries increased in as-crept alloy due to the presence of grain rotation and dislocation cells.