Three-dimensional analysis of grain structure and texture of additively manufactured 316L austenitic stainless steel

This paper aims at an in-depth analysis of grain structure and texture of 316 L austenitic stainless steel produced by the powder bed based additive manufacturing in three dimensions. The modeling framework adopted for this purpose combines the finite-difference heat solver with modified cellular automata describing the grain structure formation. The model is validated against the data on the experimental microstructure of 316 L steel produced by selective laser melting. The simulated specimen exhibits the major 011100 Goss texture and minor 001100 cube texture components, with the grains tending to orient along the build direction. The study explores the ways in which this specific additively manufactured microstructure can be formed, focusing on the epitaxial solidification taking place during additive manufacturing and preferred growth directions of the grains. Furthermore, the paper attempts to show that no nucleation ahead of the solidification front is necessary for forming fine grains in additively manufactured microstructures.