Microstructure of the 321 stainless steel samples obtained by electron-beam 3D-printing

In the paper, the formation of the gradient structure of the sample from 321 stainless obtained by the electron-beam additive manufacturing method is researched. For obtaining a high-quality product by the method of additive manufacturing, it is necessary to define possible values of electron-beam 3D-printing parameters. The macrostructure images show the layers of printing, but it is difficult to differentiate the individual elements of the sample structure. Upon further investigation, differences in the microstructure in the direction of sample growth in the next layer were revealed. According to X-ray analysis, the final sample obtained by electron-beam 3D-printing is in two-phase state: α- and γ-Fe. The proportion of the α-Fe phase in the lower part of the sample is 4.2 % higher than in the upper part. This indicates a recrystallization growth of the grain structure of the material.