About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
|
Symposium
|
Additive Manufacturing: Large-Scale Metal Additive Manufacturing
|
Presentation Title |
Towards Understanding Microstructure Evolution during Wire Arc Additive Manufacturing of Maraging 250 Thin-wall Parts |
Author(s) |
Yao Xu, Brajendra Mishra, Sneha Narra |
On-Site Speaker (Planned) |
Yao Xu |
Abstract Scope |
Wire arc additive manufacturing has recently garnered interest due to near-net-shaped manufacturing of large-scale components. It has higher deposition rates and lower feedstock costs than powder bed fusion (PBF) processes. At the same time, the temperature build-up during layer-by-layer fabrication is higher compared to the PBF processes. Hence, it is critical to assess the impact of thermal cycles and heat accumulation on microstructure and properties. In this work, microstructure characterization of Maraging Steel 250 thin-wall parts was performed to explain the decrease in hardness with wall height. Major observations focus on wall height-dependent prior austenite grain size, tempered martensite and retained austenite phases, and precipitates. Also, the thermal history of each layer was estimated using a conduction-based heat transfer model to explain the observed microstructure. This work establishes a comprehensive understanding of the effect of thermal cycles and heat accumulation on the as-fabricated microstructure of Maraging Steel 250 parts. |