Solidification behavior and texture of 316L austenitic stainless steel by laser wire directed energy deposition

Published

April 18, 2024

Author(s)

Olivia DeNonno, Alec Saville, Jake Benzing, Jonah Klemm-Toole, Zhenzhen Yu

Abstract

The solidification behavior and crystallographic texture of 316L austenitic stainless steel builds fabricated via laser-wire directed energy deposition additive manufacturing (AM) were investigated. Shielding gas set-up and build type (single-track vs. multi-track) were varied, which led to changes in the solidification conditions and the final build compositions. Primary δ-ferrite solidification is predicted based on equilibrium thermodynamic predictions of the bulk feedstock composition. However, the increased solidification velocity of the AM process promotes a solidification mode transition from primary δ-ferrite to primary austenite. Skeletal δ-ferrite and lathy δ-ferrite associated with primary δ-ferrite solidification and interdendritic δ-ferrite associated with primary austenite solidification were observed among the laser-wire directed energy deposition walls. Skeletal and interdendritic δ-ferrite exhibited a (001)δ // (001)γ parallel relationship with austenite and a 001} solidification texture aligned with the build direction for both austenite and δ-ferrite. Lathy δ-ferrite exhibited a Kurdjumov-Sachs orientation relationship, (101)δ//(111)γ, with austenite due to austenite nucleation in the solid-state. It is shown that the solidification behavior of AM 316L is accurately represented by as-built composition data and a dendrite growth model, which combined, encompasses the compositional and solidification condition impacts on the solidification pathway.

Citation

Materials Characterization

Volume

211

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.matchar.2024.113916

Local Download

Keywords

Directed energy deposition, Solidification, Crystallographic texture, Stainless steel, Dendrite tip undercooling

Citation

DeNonno, O. , Saville, A. , Benzing, J. , Klemm-Toole, J. and Yu, Z. (2024), Solidification behavior and texture of 316L austenitic stainless steel by laser wire directed energy deposition, Materials Characterization, [online], https://doi.org/10.1016/j.matchar.2024.113916, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936677 (Accessed December 21, 2024)