ELECTRON BEAM PROCESSING OF DIFFUSION BOROALUMINIZING LAYERS ON THE SURFACE OF STEEL 5KHNM

The hardening of the surface of samples made of die steel 5KhNM by a combined method is considered, which consists of sequential thermal-chemical treatment (TCT) followed by modification of the resulting diffusion layer using pulsed electron beam processing using an electron source with a plasma cathode based on a low-pressure arc discharge. Electron beam processing was carried out in the SOLO experimental installation, which is included in the list of unique electrophysical installations in Russia. The results of local structural-phase transformation of diffusion boroaluminizing layers due to high-speed heating by an electron beam of millisecond duration are presented. A comparative analysis of the structure of the diffusion layer after thermal -chemical treatment and subsequent modification of the layer with a pulsed electron beam was carried out. Microhardness was studied, and the phase state of the diffusion layer was assessed before and after electron beam exposure. Electron beam treatment (EBT) of the diffusion layer leads to an increase in micro-hardness values, the maximum value of which reaches 1400 HV, and to a decrease in surface roughness values in the Ra parameter (up to seven times). After electron beam treatment of the diffusion layer, the Fe₂B phase and intermetallic phases FeAl, Fe₂AlCr, CrSi₂ are formed, which have high heat resistance, wear resistance and corrosion resistance.

1. Bao Z.-J., Yang H.-Y., Dong B.-X., Chang F., Li C.-D., Jiang Y., Chen L.-Y., Shu S.-L., Jiang Q.-C., Qiu F. Development trend in composition optimization, microstructure manipulation, and strengthening methods of die steels under lightweight and integrated die casting. Materials. 2023;16(18):6235. https://doi.org/10.3390/ma16186235

2. Weinert A., Tormey D., O’Hara C., McAfee M. Condition monitoring of additively manu-factured injection mould tooling: A review of demands, opportunities and potential strate-gies. Sensors. 2023;23(4):2313. https://doi.org/10.3390/s23042313

3. Milinović A., Stojšić J., Kladarić I., Matijević B. Evaluation of boride layers on C70W2 steel using a new approach to characterization of boride layers. Materials. 2022;15(11):3891.

4. https://doi.org/10.3390/ma15113891

5. Polyansky I.P., Vikhrev R.O., Sizov I.G. Structure and properties of boride coatings on tool steels. Polzunovsky bulletin. 2023;1:171–177. (In Russ.). https://doi.org/10.25712/ASTU.2072-8921.2023.01.021

6. Pashechko M., Dziedzic K., Jozwik J. Analysis of wear resistance of borided steel C45. Mate-rials. 2020;13(23):5529.

7. https://doi.org/10.3390/ma13235529

8. Pugacheva N.B., Bykova T.M. Investigation of boration methods, analysis of the structure and properties of the coatings obtained. Diag-nostics, Resource and Mechanics of Materials and Structures. 2020,2:38–60. (In Russ.).

9. https://doi.org/10.17804/2410-9908.2020.2.038-060

10. Mednikov A., Tkhabisimov A., Kalakuckaya O., Zilova O., Kachalin G. Studies of boriding using possibility to increase the corrosion re-sistance of cast steel 20GL. Coatings. 2022;12(11):1789. https://doi.org/10.3390/coatings12111789

11. Bartkowska A., Bartkowski D., Przestacki D., Hajkowski J., Miklaszewski A. Microstructural and mechanical properties of B-Cr coatings formed on 145Cr6 tool steel by laser remelting of diffusion borochromized layer using diode laser. Coatings. 2021;11(5):608.

12. https://doi.org/10.3390/coatings11050608

13. Günen A., Ergin Ö. A comparative study on characterization and high-temperature wear behaviors of thermochemical coatings applied to cobalt-based haynes 25 superalloys. Coat-ings. 2023; 13(7):1272.

14. https://doi.org/10.3390/coatings13071272

15. Konovalov S.V., Ivanov Yu.F., Grmov V.E., Shlyarova Yu.A., Kondratova O.A., Kirillova A.V. Structural-phase states and properties of high-entropy CrMnFeCoNi alloy after elec-tron-beam processing. Bulletin of the Siberian State Industrial University. 2022;2(40):47–56. (In Russ.).

16. Tarasov A.D., Petryakova E.A., Ivanov Yu.F., Kry-sina O.V., Prokopenko N.A. Electron beam surface treatment of metal materials manufactured by addi-tive method. News of universities. Physics. 2022;65(11(780)):168–175. (In Russ.).

17. https://doi.org/10.17223/00213411/65/11/168

18. Valkov S., Dechev D., Ivanov N., Bezdushnyi R., Ormanova M., Petrov P. Influence of beam power on young’s modulus and friction coefficient of Ti–Ta alloys formed by electron-beam surface alloying. Metals. 2021;11(8):1246. https://doi.org/10.3390/met11081246

19. Nevsky S.A., Sarychev V.D., Gromov V.E. Combined hydrodynamic instabilities and their role in the formation of micro- and nanostructures of materials under plasma in-fluences. Bulletin of the Siberian State Indus-trial University. 2023;1(43):10–16. (In Russ.). http://doi.org/10.57070/2304-4497-2023-1(43)-10-16

20. Konovalov S., Ivanov Y., Gromov V., Pan-chenko I. Fatigue-induced evolution of ALSI 310S steel microstructure after electron beam treatment. Materials. 2020;13(20):4567. https://doi.org/10.3390/ma13204567

21. Cai J.,Yao Y., Gao C., Lyu P., Meng X., Guan Q., Li Y., Han Z.Comparison of microstruc-ture and oxidation behavior of NiCoCrAlYSi laser cladding coating before and after high-current pulsed electron beam modification. Journal of alloys and Compounds. 2021;881:160651. https://doi.org/10.1016/J.JALLCOM.2021.160651

22. Ulukhanov N., Mishigdorjiin U., Tikhonov A., Shustov A., Pyatykh A. Modification of the surface layer of stamped steels by creating B-Al layers by chemical and thermal treat-ment. Reinforcing technologies and coatings. 2021;17(12(204)):557–564. (In Russ.). https://doi.org/10.36652/1813-1336-2021-17-12-557-564

23. Koval N.N., Devyatkov V.N., Vorobyev M.S. Electron sources with plasma grid emitters: progress and prospects. Russ Phys J. 2021;63:1651–1660. https://doi.org/10.1007/s11182-021-02219-3

24. Vorobyov M., Koval T., Shin V., Moskvin P., Tran M.K.A., Koval N., Ashurova K., Doroshkevich S., Torba M. Controlling the Specimen surface tempera-ture during irradiation with a submillisecond electron beam produced by a plasma-cathode electron source. IEEE Transactions on Plasma Science. 2021;49(9):2550–2553. https://doi.org/10.1109/TPS.2021.3089001

25. Vorobyov M.S., Moskvin P.V., Shin V.I., Ko-val T.V., Devyatkov V.N., Doroshkevich S.Y., Koval N.N., Torba M.S., Ashurova K.T. Nega-tive current feedback in the accelerating gap in electron sources with a plasma cathode. Technical Physics. 2022;67(6):747–752. http://dx.doi.org/10.21883/TP.2022.06.54422.14-22

26. Bannikova Yu.A., Ivanov Yu.F., Romanov D.A., Kormyshev V.E. Mechanical and tribo-logical properties of the boron layer deposited on low-carbon steel. Fundamental problems of modern materials science. 2019;16(3):387–393. (In Russ.).