The Features of Structure Formation in Chromium-Nickel Steel Manufactured by a Wire-Feed Electron Beam Additive Process

Resumo

The investigations of the metal macro- and microstructure are performed using the specimens manufactured from the 302 stainless steel via electron-beam additive layer manufacturing in a laboratory setup ensuring 3D printing of articles with circular interpolation. Successive padding of metal results in the formation of a relief representing alternate crests and troughs on the lateral side of the specimen. It is shown by the methods of optical and scanning electron microscopy that the metal of these specimens has a complex heterogeneous dendritic structure containing both relatively coarse grains and subgrains and finer grains. The fine structure of the resulting metal is characterized by a combination of the regions with marked banding and those with nearly regular-shaped grains both in the longitudinal and transverse directions. The grains of more equiaxed shapes are about 5–10 μm in size. It is hypothesized that an application of the additive process would allow manufacturing textured structures with predetermined orientations.