Structural and mechanical properties of stainless steel formed under conditions of layer-by-layer fusion of a wire by an electron beam

OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 23 No. 4 2021 Fig. 11. Microhardness measurements along cross sections XOZ and YOZ The structure primarily contains columnar grains directed along the deposition of layers along the height. The structural studies have revealed two-phase composition. The main phase is an austenitic matrix based on γ - Fe with an FCC -lattice and inclusions of high-temperature ferrite  - Fe with a BCC lattice of various shapes. The needle-like, granular and vermiculite forms of δ -ferrite were identi fi ed. The sharp interface between the wire layers is not pronounced; however, there are small differences in the phase composition. These alterations affect mechanical properties. Microhardness tests have shown that it alters within 10%. The results allowed establishing that the use of electron-beam 3D-printing for manufacturing parts from AISI 308LSi steel provides the structure similar to that of cast austenitic steels. There are no macro-defects and the number of gas pores is small. References 1. Murr L.E.Metallurgyof additivemanufacturing: examples fromelectronbeammelting. AdditiveManufacturing , 2015, vol. 5, pp. 40–53. DOI: 10.1016/j.addma.2014.12.002. 2. Milevski J.O. Additive manufacturing of metals: from fundamental technology to rocket. nozzles, medical implants and custom jewelry . Cham, Springer, 2017. 351 p. ISBN 978-3-319-58205-4. 3. Zhang Y., Wu L., Guo X., Kane S., Deng Y., Jung Y.-G., Lee J.-H., Zhang J. Additive manufacturing of metallic materials: a review. Journal of Materials Engineering and Performance , 2018, vol. 27, iss. 1, pp. 1–13. DOI: 10.1007/ s11665-017-2747-y. 4. DebRoy T., Mukherjee T., Wei H.L., Elmer J.W., Milewski J.O. Metallurgy, mechanistic models and machine learning in metal printing. Nature Reviews Materials , 2020, vol. 6, pp. 48–68. DOI: 10.1038/s41578-020-00236-1. 5. Edwards P., O’Conner A., Ramulu M. Electron beam additive manufacturing of titanium components: properties and performance. Journal of Manufacturing Science and Engineering , 2013, vol. 135, iss. 6, p. 061016. DOI: 10.1115/1.4025773. 6. Tavlovich B., Shirizly A., Katz R. EBW and LBW of additive manufactured Ti6Al4V products. Welding Journal , 2018, vol. 97, iss. 6, pp. 179–190. DOI: 10.29391/2018.97.016. 7. Peleshenko S., Korzhyk V., Voitenko O., Khaskin V., Tkachuk V.Analisis of the current state of additive welding technologies for manufacturing volume metallic products. Eastern-European Journal of Enterprise Technologies , 2017, vol. 3/1, iss. 87, pp. 42–52. DOI: 10.15587/1729-4061.2017.99666. 8. Wang J., Pan Z., Wei L., He S., Cuiuri D., Li H. Introduction of ternary alloying element in wire arc additive manufacturing of titanium aluminide intermetallic. Additive Manufacturing , 2019, vol. 27, pp. 236–245. DOI: 10.1016/j.addma.2019.03.014. 9. Chekir N., Sixsmith J.J., Tollett R., Brochu M. Laser wire deposition of a large Ti-6Al-4V space component. Welding Journal , 2019, vol. 28, iss. 6, pp. 172–180. 10. Taminger K.M., Ha fl ey R.A. Electron beam freeform Fabrication for cost effective near-net shape manufacturing. NATO/RTO AVT-139 Specialists’ Meeting on Cost Effective Manufacture via Net Shape Processing , Amsterdam, 2006, p. 16.