Level-Set modeling of grain growth in 316L stainless steel under different assumptions regarding grain boundary properties

TL;DR

This study compares two finite element level-set models for grain growth in 316L stainless steel, examining effects of grain boundary properties and microstructure generation methods on grain size and morphology.

Contribution

It introduces and compares two FE-LS formulations with different assumptions on grain boundary properties, highlighting the impact on grain growth predictions.

Findings

Anisotropic formulation better matches experimental disorientation distribution.

Both models produce similar mean grain sizes and distributions.

Heterogeneous GB mobility influences grain morphology and twin boundary evolution.

Abstract

Two finite element level-set (FE-LS) formulations are compared for the modeling of grain growth of 316L stainless steel in terms of grain size, mean values and histograms. Two kinds of microstructures are considered, some are generated statistically from EBSD maps and the others are generated by immersion of EBSD data in the FE formulation. Grain boundary (GB) mobility is heterogeneously defined as a function of the GB disorientation. On the other hand, GB energy is considered as heterogeneous or anisotropic, respectively defined as a function of the disorientation and both the GB misorientation and the GB inclination. In terms of mean grain size value and grain size distribution (GSD), both formulations provide similar responses. However, the anisotropic formulation better respects the experimental disorientation distribution function (DDF) and predicts more realistic grain morphologies. It was also found that the heterogeneous GB mobility described with a sigmoidal function only affects the DDF and the morphology of grains. Thus, a slower evolution of twin boundaries (TBs) is perceived.