Simulation of Microstructure of Nickel Base Alloy 706 in Production of Power Generation Turbine Disks

In die forging the conditions of strain and of the subsequent heat cycle have a significant influence on the structure and properties of the final product, that is why the determination and modelhng of gram size development during and after deformation is of primary interest. In this paper we present the simulation procedure and the methodology used to develop a model which can predict microstructural changes in alloy 706 during hot forming. High temperature compression test samples were used to develop a constitutive equation for the alloy 706 which was then applied via a finite element model to firstly simulate industrial forging process and tinally optimize it. Important parameters such as critical deformation to initiate recrystallization have been determined. The model was found to accurately predict the recrystallized gram size and the percentage of recrystallization on compression test samples as well as on industrial parts. Superalloys 2003 Edited by T.M. Pollock, R.D. Kissinger, R.R. Bowman, K.A. Green, M. McLean, S. Olson, and J.J. Schirra TMS (The Minerals, Metals &Materials Society), 20@3