OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 1 2023 Ta b l e 5 Roughness of the specimens after TCIT (Fig. 11-13) Type of teatment Steel 45 (0.45% C) Steel U10 (1.0% C) 0.5C-Cr-Ni-Mn steel Ra, мкм Original, without teatment 0.06 0.062 0.084 Borocoppering for 3 hours 0.2 0.187 0.175 Borocoppering for 4 hours 0.16 0.201 0.273 Borocoppering for 5 hours 0.176 0.189 0.211 Conclusion Based on the conducted studies, it is found that saturation of specimens from Steel 45 (0.45% C), Steel U10 (1.0% C) and 0.5C-Cr-Ni-Mn steel for 3, 4 and 5 hours leads to the formation of diffusion layers, the thickness of which varies from 110 to 230 µm. It is found that the increase in the thickness of the diffusion layer on Steel 45 (0.45% C) is 41%, with an increase in the time of treatment by 2 hours. On Steel U10 (1.0% C) and 0.5C-Cr-Ni-Mn steel, the values of the layer thickness increase were 40 and 77 %, respectively. For these grades of steels, a longer soaking time during borocoppering is recommended. It is established that during the diffusion boromedning for 4 hours, the greatest increase in the thickness of the diffusion layer is observed. The study of microtopography revealed that the roughness after borocoppering increases to Ra 0.16–0.2 µm at the initial Ra 0.06–0.08 µm for Steel 45 (0.45% C), Steel U10 (1.0% C) and 0.5C-Cr-Ni-Mn steel, while the duration of the process does not affect the increase in roughness. References 1. Busby P.E., Warga M.E., Wells C. Diffusions and solubility of boron in iron and steel. JOM, 1953, vol. 5, pp. 1463–1468. DOI: 10.1007/BF03397637. 2. Prince M., Surya Raj G., Yaswanth Kumar D., Gopalakrishnan P. Boriding of steel: improvement of mechanical properties – a review. High Temperature Material Processes, 2022, vol. 26 (2), pp. 43–89. DOI: 10.1615/ HighTempMatProc.2022041805. 3. Shevchuk E.P., Plotnikov V.A., Bektasova G.S. Diffuziya bora pri borirovanii uglerodistoi stali [Boron diffusion during carbon steel boriding]. Izvestiya Altaiskogo gosudarstvennogo universiteta = Izvestiya of Altai State University, 2021, no. 1 (117), pp. 64–65. DOI: 10.14258/izvasu(2021)1-10. 4. Yu L.G., Chen X.J., Khor K.A., Sundararajan G. FeB/Fe2B phase transformation during SPS pack-boriding: Boride layer growth kinetics. Acta Materialia, 2005, vol. 53, pp. 2361–2368. DOI: 10.1016/j.actamat.2005.01.043. 5. Bernal-Ponce J., Irvin-MartinezA., Vera-Cardenas E., Garcia-BarrientosA., Medina-FloresA., Bejar-Gomez L., Borjas-Garcia S. A microstructure comparison of Iron borides formed on AISI 1040 and D2 steels. Microscopy and Microanalysis, 2015, vol. 21, suppl. 3, pp. 1759–1760. DOI: 10.1017/S1431927615009575. 6. Mishustin N.M., Ivanaiskii V.V., IshkovA.V. Sostav, struktura i svoistva iznosostoikikh pokrytii, poluchennykh na stalyakh 65G i 50KhGA pri skorostnom TVCh-borirovanii [Composition, structure and properties of wearresistant coatings obtained on steels 65G and 50KhGAwith high-speed high-frequency boriding]. Izvestiya Tomskogo politekhnicheskogo universiteta = Bulletin of the Tomsk Polytechnic University, 2012, vol. 320, no. 2, pp. 68–72. 7. Balanovskii A.E., Vu V. Plazmennaya poverkhnostnaya tsementatsiya s ispol’zovaniem grafitovogo pokrytiya [Plasma surface carburizing with graphite paste]. Pis’ma o materialakh = Letters on Materials, 2017, vol. 7, no. 2, pp. 175–179. DOI: 10.22226/2410-3535-2017-2-175-179. 8. Kolosov A.D., Gozbenko V.E., Shtayger M.G., Kargapoltsev S.K., Balanovskiy A.E., Karlina A.I., Sivtsov A.V., Nebogin S.A. Comparative evaluation of austenite grain in high-strength rail steel during welding, thermal processing and plasma surface hardening. IOP Conference Series: Materials Science and Engineering, 2019, vol. 560. DOI: 10.1088/1757-899X/560/1/012185.
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