Evaluation of the Suitability of High-Temperature Post-Processing Annealing for Property Enhancement in LPBF 316L Steel: A Comprehensive Mechanical and Corrosion Assessment

作者：Bohdan Efremenko, Yu. G. Chabak, Ivan Petryshynets, Tianliang Zhao, V. G. Efremenko, Kaiming Wu, Tao Xia, Miroslav Džupon, Sundas Arshad · 发表于：Metals · 年份：2025 · DOI：10.3390/met15060684 · 被引用次数：5 · 研究领域：Additive Manufacturing Materials and Processes、High Entropy Alloys Studies、Welding Techniques and Residual Stresses

This study aims to comprehensively assess the suitability of post-processing annealing (at 900–1200 °C) for enhancing the key properties of 316L steel fabricated via laser powder bed fusion (LPBF). It adopts a holistic approach to investigate the annealing-driven evolution of microstructure–property relationships, focusing on tensile properties, nanoindentation hardness and modulus, impact toughness at ambient and cryogenic temperatures (−196 °C), and the corrosion resistance of LPBF 316L. Annealing at 900–1050 °C reduced tensile strength and hardness, followed by a moderate increase at 1200 °C. Conversely, ductility and impact toughness peaked at 900 °C but declined with the increasing annealing temperature. Regardless of the annealing temperature and testing conditions, LPBF 316L steel fractured through a mixed transgranular/intergranular mechanism involving dimple formation. The corrosion resistance of annealed steel was significantly lower than that in the as-built state, with the least detrimental effect being observed at 1050 °C. These changes resulted from the complex interplay of annealing-induced structural transformations, including elimination of the cellular structure and Cr/Mo segregations, reduced dislocation density, the formation of recrystallized grains, and the precipitation of nano-sized (MnCrSiAl)O3 inclusions. At 1200 °C, an abundant oxide formation strengthened the steel; however, particle coarsening, combined with the transition of (MnCrSiAl)O3 into Mo-...