Modeling of Ni-Cr-Mo based alloys: Part II - Kinetics

The CALPHAD approach is applied to kinetic studies of phase transformations and to aging of prototypes of Ni-Cr-Mo-based alloys selected for waste disposal canisters in the Yucca Mountain Project (YMP). Based on a previous study on alloy stability for several candidate alloys, the thermodynamic driving forces, together with a newly developed mobility database, have been used to analyze diffusion-controlled transformations in these Ni-based alloys. Results on precipitation of the Ni2Cr-ordered phase in Ni-Cr and Ni-Cr-Mo alloys, and of the complex P and σ phases in a surrogate of Alloy 22 are presented, and the output from the modeling are compared with experimental data on aging.