OBRABOTKAMETALLOV Vol. 25 No. 1 2023 technology mium, titanium and other elements. This range can be reduced by decreasing the ferrite stabilizing chromium in steel and slightly increasing carbon within the limits of allowable composition (but not higher than the value recommended for eliminating intergranular corrosion of 0.05 %) (Fig. 4). In order to minimize the amount of δ-ferrite in the structure and remove excess magnetization, austenization is carried out – soaking at temperature of 1,050 °C. This temperature is outside the calculated range, however, even with such soaking, the ferrite phase does not completely dissolve for kinetic reasons. The residual particles of the δ-phase spheroidize and decrease in size. The results comparison of spectral analysis, metallographic studies and thermodynamic simulation show that the increased amount of ferrite phase in 12-Cr18-Ni10-Ti steel corresponds to a wide calculated temperature range of its existence (about 200 °C). In the case of a shortened range (100 °C or less), the presence of ferrite is minimal and the magnetization is low. However, even in the case of highFig. 3. Microstructure of a rod Ø 3 mm made of steel grade 12-Cr18-Ni10-Ti after austenization Fig. 4. Dependence of the content of δ-ferrite in steel 12-Cr18-Ni10-Ti at different alloying contents: a – the effect of titanium; b – the effect of chromium; c – the effect of carbon а b с
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