Effect of B and Zr additions and homogenization treatment on the carbide morphology of a vacuum cast Co-Cr-W-Ni superalloy

摘要

The influence solution heat treatment (1200 degrees C) on the evolution of carbide morphology and creep tensile properties of a vacuum cast Co-Cr-W-Ni base superalloy with and without of B and Zr additions has been investigated. The experimental evidence, shows that compared to the as cast microstructure, the creep life at a temperature of 750 degrees C, the carbide morphology and distribution are affected by the B and Zr additions as well as the solution treatment. After solution treating the alloy without additions, a finer carbide distribution along the interdendritic arms was observed. On the contrary, the additions of B and Zr impact the carbide morphology as well as its distribution, precipitating within the dendrites and at interdendritic regions. Due to this, the creep life and creep deformation of sample with additions are 12.5 and 2.7 times higher compared to the sample without additions respectively.