About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
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Symposium
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Additive Manufacturing of Metals: Microstructure, Properties and Alloy Development
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Presentation Title |
Role of Manganese Composition on the Strain-Controlled Fatigue Life in Additively Manufactured 316L Austenitic Stainless Steel |
Author(s) |
Ian J. Wietecha-Reiman, Todd A. Palmer |
On-Site Speaker (Planned) |
Ian J. Wietecha-Reiman |
Abstract Scope |
Manganese compositions in additively manufactured 316L austenitic stainless steels typically fall in a range between (1 and 2) mass fraction (%). Decreases in manganese composition to a level on the order of 0.5 mass fraction (%) leads to the replacement of these spinel oxides with alpha-tridymite and Cr2N phases. The emergence of these phases activates new fatigue failure mechanisms that vary with locations within the specimen and leads to a decrease in the strain-controlled fatigue life when process porosity is mitigated. In the fine grain structures present within the contour passes at the specimen edges, intergranular failures are primarily initiated along austenite grain boundaries populated with micro- and nano-sized Cr2N and Mn-bearing spinel oxide phases. Decreases in the build angle of individual test specimens impacts the width of this contour region and leads to an increase in the area of brittle intergranular failure and a corresponding decrease in fatigue lives. |