Correlation between Cellular Structure Morphology and Anisotropic Yield in Additively Manufactured Austenitic Stainless Steel

Abstract

The complex cellular structure of additively manufactured austenitic stainless steel, SUS316L, is due to the complicated thermal cycles involved. Cellular structure results from epitaxial growth, and cellular structure morphology depends on the directions of cell growth and observation. The probability of determining a specific cellular structure morphology of additively manufactured specimens is dependent on the grain orientation due to the directional cellular structure. Therefore, the cellular structure morphology affects the Taylor factor and mechanical properties such as hardness and yield strength. Additively manufactured austenitic stainless steel exhibits anisotropic yield strengths in the building and transverse directions, which is attributed to the cellular structure morphology and Taylor factor. The equiaxed type and elongated type exhibit a lower and high Taylor factor, respectively. The transverse direction plane presents <111> and <101> textures with a high Taylor factor, whereas the building direction plane presents a <001> texture with a relatively low Taylor factor.