OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 1 2023 Ta b l e 4 The elemental composition of the diffusion layer on 0.5C-Cr-Ni-Mn steel after 4 hours of borocoppering (fig. 7, c) Points of the spectrum Chemical elements, mass % В C Al Cr Ni Cu Mo Fe 1 16.43 0.35 0.3 0.66 0.67 2.6 0.57 78.42 2 14.77 0.15 0.51 0.66 0.67 - 0.14 83.1 3 12.05 0.06 – 0.53 0.51 0.51 0.27 86.07 4 5.98 0.03 – 0.62 0.31 – 0.34 92.72 5 1.35 0.41 – 0.63 0.46 – 0.25 96.9 6 0.21 0.37 0.56 0.59 0.57 0.09 0.07 97.54 7 – 0.4 0.58 0.4 0.56 0.54 – 97.52 Fig. 8. XRD pattern of the specimen of Steel 45 (0.45% C) after borocoppering for 4 hours that copper was detected in free form, which confirms the assumptions indicated in [21], where it does not form thermally stable compounds with boron, iron and carbon. As a result of the study of microgeometry, three-dimensional microtopographs were obtained, as well as profilograms of the surfaces of the specimens after TCT (see Fig. 11–13). Roughness was estimated by the parameter Ra (Table 5). The roughness of Steel 45 (0.45% C), Steel U10 (1.0% C) and 0.5C-Cr-Ni-Mn steel in the initial state before the TCT was comparable and the Ra values are in the range of 0.06–0.084 µm (Fig. 11, a, 12, a, 13, a). After TCT, there is an increase in the heights of micro-dimensions compared to the initial specimens for all the materials under consideration and the processing time (Fig. 11, b–d, 12, b–d, 13, b–d). After borocoppering, an increase in the Ra parameter was established by 2–3 times compared to the initial specimens
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