February 2022 Volume 4

FORGING RESEARCH

To test this hypothesis, a "virtual single colony" was simulated under different loading scenarios. As an initial test, uniaxial compression along many dierent loading directions for the single colony was simulated and the resulting plastic rotations were predicted. Figure

2 illustrates the initial setup for the uniaxial compression virtual experiment. These results were published as an invited manuscript, Reference [1], and served as the motivation and foundation for the additional work conducted herein.

Figure 1: Hypothesized relationship between plastic rotation of that α and β phases and the spheroidization behavior duri hot def rmation.

Figure 2: Previously demonstrated uniaxial compression simulation setup. Experimental results from Refer- ence [2] are overlaid in gray on the rightmost figure; a strong match is observed, suggesting that this method has promise for predicting orientation-dependent globularization. Figures adapted from Reference [1]. Figure 2: Previously demonstrated uniaxial compression simulation setup. Experimental results from Reference [2] are overlaid in gray on the rightmost figure; a strong match is observed, suggesting that this method has promise for predicting orientation-dependent globularization. Figures adapted from Reference [1].

Simulation of different + β single colony orientations for each loading scenarioproduces awide variety ofmetrics of plastic rotation, as illustrated in Figure 3 for the case of uniaxial compression. These previously published results will be used as a baseline for comparison

in the following scenarios. For compactness, only the angular deviation from initial BOR (left column, middle row in Figure 3) will be used for comparison in this report. Other outputs are available upon request.

as summarized in Figure 1. In α − β colonies where little plastic rotation of either phase is exp ct d, neith r microtextured region (MTR) evol tion nor spheroidization would be predicted. In colonies where plastic rotation of the α and β phases is predicted to occur in opposite directions, both MTR evolution and breakdown is predicted. Finally, in colony orientations where significant plastic rotation in similar directions is predicted for both the α and β phases, MTR evolution will occur but little globularization would be expected. To test this hypothesis, a “virtual single colony” was simulated under different loading scenarios. As an initial test, uniaxial compression along many different loading directions for the single colony was simulated and the resulting plastic rotations were predicted. Figure 2 illustrates the initial setup for the uniaxial compression virtual experiment. These results were published as an invited manuscript, Reference [1], and served as the motivation and foundation for the additional work conducted herein. Simulation of different α + β single colony orientations for each loading scenario produces a wide variety of metrics of plastic rotation, as illustrated in Figure 3 for the case of uniaxial compression. These previously published results will be used as a baseline for comparison in the following scenarios. For compactness, only the angular deviation from initial BOR

2

Figure 3: Selected outputs of the initial uniaxial compression loading scenario. Starting in the top row, the plots represent: misorientation of the α phase from its initial orientation; misorientation of the β phase from its initial orientation; angular deviation from the initial Burgers orientation relationship (BOR) at the end of compression; maximum deviation from the initial BOR achieved at any point during deformation; classification of deformation behavior into stable orientations (dark gray), corotation (light gray), or anti- rotation (red); and a schematic illustrating the initial orientation of the α + β phases. Figure 3: Selected o tputs of the initial uniaxial compr ssion loadi g scenario. Sta ting i the top row, the pl ts represe t: misorientation f the phase from its initial orientation; mis rientation of he β phase from ts initial orientation; angular dev ation f om he initial Bu g rs Or e tation Relationship (BOR) at the end of compression; maximum devi ti n from the initial BOR achieved at any point during deformation; classication of deformation behavior into stable orientations (dark gray), corotation (light gray), or anti-rotation (red); and a schematic illustrating the initial orientation of the + β phases.

FIA MAGAZINE | FEBRUARY 2022 79

(left column, middle row in Figure 3) will be used for comparison in this report. Other