Grain refinement of stainless steel by strontium oxide heterogeneous nucleation site particles during laser-based powder bed fusion

• Published in: Journal of materials processing technology Vol. 308; p. 117700
• Main Authors: Watanabe, Yoshimi, Yuasa, Tomoki, Sato, Hisashi, Okubo, Satoshi, Fujimaki, Kengo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2022; Elsevier BV
• Subjects: 316 L (Fe-17%Cr-11%Ni-2%Mo) stainless steel; Chromium; Grain refinement; Grain size; Heterogeneous nucleation site particles; Laser applications; Laser-based powder bed fusion (PBF-LB); Lasers; Mechanical properties; Microstructure; Molybdenum; Nucleation; Powder beds; Rapid prototyping; Specific gravity; SrO; Stainless steel; Stainless steels; Steel alloys; Strontium oxides; Grain size; Laser-based powder bed fusion (PBF-LB); SrO; 316 L (Fe-17%Cr-11%Ni-2%Mo) stainless steel; Heterogeneous nucleation site particles
• ISSN: 0924-0136; 1873-4774
• DOI: 10.1016/j.jmatprotec.2022.117700

The effect of SrO heterogeneous nucleation site particles on the formability, microstructure, and mechanical properties of additive manufactured 316 L (Fe-17%Cr-11%Ni-2%Mo) stainless steel samples produced by laser-based powder bed fusion has been investigated. The relative densities of the samples produced with SrO under medium and low energy density conditions were higher than those produced without SrO, although addition of SrO negatively affected the relative density under the high energy density condition. SrO addition showed significant grain refinement (about 15%) on the 316 L stainless steel alloy during laser-based powder bed fusion. Although it was found that SrO had a negative effect on the mechanical properties under the high energy density condition, significant improvements of the microstructure and mechanical properties was achieved by addition of SrO under the low energy density condition with high scanning velocity. It can be concluded that addition of heterogeneous nucleation site particles is a potential way to control the microstructure and mechanical properties of samples made by laser-based powder bed fusion.