OBRABOTKAMETALLOV technology Vol. 26 No. 2 2024 Fig. 1. Scheme of the filling strategy for growing specimens from steel 0.12-Cr18-Ni10-Ti (AISI 321) Ta b l e 2 Chemical composition of the powder Chemical element, mass % Fe Cr Ni Mn Si Ti Cu V Mo C Bal. 18.19 10.67 1.14 0.54 0.51 0.18 0.10 0.17 0.06 out – the location of the test specimens was determined and cut out randomly. The specimens were certified at room temperature using various research equipment. As a result, data on thermophysical and physical and mechanical properties were obtained (Table 3). The mechanical properties of steel 0.12-Cr18-Ni10-Ti (AISI 321) in its initial state and after heat treatment correspond to OST 95-29-72 “Workpieces made of corrosion-resistant steels”. Blanks with a size of 160×80×8 mm were used directly for milling. The thermophysical properties of steel 0.12-Cr18-Ni10-Ti (AISI 321) were determined at a temperature of 20 °C. The following values were obtained: density 7.91 g/cm3; thermal conductivity coefficient 14 W/ m∙°C; specific heat capacity 473 J/kg∙°C. Figure 2 shows the microstructure of the specimen in the ZY plane and in the ZX plane. The study of the microstructure showed the two-phase nature of additive specimens: an austenitic matrix based on γ-Fe with a face-centered cubic lattice (FCC) and high-temperature rack and vermicular δ-ferrite with a body-centered cubic lattice (BCC), which is also confirmed by a diffractogram of the specimens (Fig. 3). Mainlyδ-ferrite is formed at the fusion boundaries. Titanium carbides TiC are present in the specimens. Ta b l e 3 Mechanical properties of steel 0.12-Cr18-Ni10-Ti (AISI 321) Condition Sampling direction (see Fig. 1) Hardness, HB σ0.2, MPa UTS (σUTS), MPa δ5, % KCU, J/cm2 Plate (OST 95-29-72) – ≈180–190 246 520 37 215–372 LMD X axis 193–205 412±20 627±34 48.2±1.5 271±18 Z axis 387±16 606±28 51.2±2 286±21
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