Grain boundary character correlated carbide precipitation and mechanical properties of Ni-20Cr-18W-1Mo superalloy

This work illustrates the grain boundary character correlated carbide precipitation and its effect on mechanical properties of a Ni-20Cr-18W-1Mo superalloy. The results show that W segregation and Cr desegregation at grain region promote the secondary M6C-typed carbide precipitation on grain boundaries. The morphologies of the intergranular carbides change from granular to plate-like with increasing of the exposure time at 1100 °C. The tensile strength and elongation have developed value peak in a relatively short exposure time within 5 h (h). The phase interface cracks in the initial stage and correspondingly deteriorate mechanical properties of the experimental Ni-20Cr-18W-1Mo superalloy during the long time aging process at elevated temperature.