Rheological Properties of the EP742-ID Alloy in the Context of Integrated Computational Materials Science and Engineering: Part II. Modeling the Compression Process of the Samples and Virtual Billets

Abstract

Part II of this work is devoted to a comparison of the results of modeling and experiment with the Guber–Mises theoretical plasticity condition during axisymmetric upsetting the samples of the EP742-ID alloy with various ratios of initial diameters d₀/h₀. The influence of initial sizes on the deformation mode of model experimental samples and virtual billets is evaluated. The results of modeling the draft of cylindrical samples (Ø15 mm) and billets (Ø300 mm) of the EP742-ID heat-resistant nickel alloy with various ratios of initial homological sizes are presented and the selection of the average tension and equivalent deformation as internal factors determining the microstructure formation is substantiated. It is shown that the squeezing axial tension component in the sample center under conditions of the initial plastic deformation of 0.2% increases larger than by a factor of 1.5 with an increase in the d₀/h₀ ratio. The experimental and calculated values of the conditional yield point, axial tension, and radial tension at a compression temperature of 1050°C depending on d₀/h₀ are found. The influence of the degree of strain and the ratio of initial sizes on the distribution of the average tension and equivalent strain over the half-height radius of the meridional section of upsetted (experimental) samples (Ø15 mm) and virtual billets (Ø300 mm) is analyzed. General principles of forecasting the microstructure to solve the problems using software complexes of process modeling when developing the upsetting modes of discs made of heat-resistant nickel alloys are described. Attention is paid to the fact that the modeling methods should be substantiated theoretically and confirmed experimentally.