Milling martensitic steel blanks obtained using additive technologies

OBRABOTKAMETALLOV Vol. 25 No. 4 2023 technology due to the elastic deformation of the MDTP system and the slight radial runout of the teeth, the maximum force of each cycle is not the same. As a result of the experimental work, the forces acting on the tool when processing specimens from heat-resistant steel obtained by the EBW wire method are determined. Patterns of changes in cutting forces during cutting with one tooth are also obtained. Important results include determining the change in the direction of the lateral component of the cutting force Pv. Since the presence of a gap in the screw pair of the transverse feed of the machine leads to vibrations, it should be reduced to a minimum. Knowing the Ph feed force obtained from the results of the tests allows calculating the necessary workpiece clamping force. This is especially important when the workpiece has low rigidity. These results are important for manufacturing enterprises when processing workpieces obtained by the EBW wire method. Conclusion The cutting forces are studied by milling the rectangular specimens produced by electron-beam surfacing of the martensitic stainless steel. Based on the experiments, the following main conclusions are drawn: 1. The structure of the specimens printed by electron-beam surfacing corresponds to temperedmartensite. 2. The magnitude of the resulting cutting force Phv for up and down milling is almost the same. But the cutting force in the feed direction Ph during up milling is significantly greater than that taking place during down milling, and the lateral force Pv during up milling is significantly less than that arising during down milling. Based on the mentioned, when processing thin-walled parts, down milling should be used. 3. In this work, using a slight deviation from the standard method of measuring the cutting forces, the dependences of the changes in forces Pz and Py during the operation of the cutter are obtained. These data allow constructing diagrams of contact stresses involving known physical components on the front surface of the tooth. The standard methodology does not provide such data. This is especially important for the process of designing a new tool. This allows calculating the tool in terms of the work devoted to the stainless steel 0.4 % C-13 % Cr. The forces Pz and Py acting on the cutter tooth are determined. As a continuation of this work, it is planned to determine the forces Pz and Py for titanium alloys obtained by the EBW wire surfacing. References 1. Alvarez L.F., Garcia C., Lopez V. Continuous cooling transformations in martensitic stainless steels. ISIJ International, 1994, vol. 34 (6), pp. 516–521. DOI: 10.2355/isijinternational.34.516. 2. Kazemipour M., Lunde J.H., Salahi S., Nasiri A. On the microstructure and corrosion behavior of wire arc additively manufactured AISI 420 stainless steel. TMS 2020 149th Annual Meeting & Exhibition Supplemental Proceedings. Springer, 2020, pp. 435–448. DOI: 10.1007/978-3-030-36296-6_41. 3. Liverani E., Fortunato A. Additive manufacturing of AISI 420 stainless steel: Process validation, defect analysis and mechanical characterization in different process and post-process conditions. The International Journal of Advanced Manufacturing Technology, 2021, vol. 117 (3–4), pp. 809–821. DOI: 10.1007/s00170-021-07639-6. 4. Saeidi K., Zapata D.L., Lofaj F., Kvetkova L., Olsen J., Shen Z., Akhtar F. Ultra-high strength martensitic 420 stainless steel with high ductility. Additive Manufacturing, 2019, vol. 29, p. 100803. DOI: 10.1016/j. addma.2019.100803. 5. Krakhmalev P., Yadroitsava I., Fredriksson G., Yadroitsev I. In situ heat treatment in selective laser melted martensitic AISI 420 stainless steels. Materials & Design, 2015, vol. 87, pp. 380–385. DOI: 10.1016/j. matdes.2015.08.045. 6. Ge J., Lin J., Chen Y., Lei Y., Fu H. Characterization of wire arc additive manufacturing 2Cr13 part: Process stability, microstructural evolution, and tensile properties. Journal of Alloys and Compounds, 2018, vol. 748, pp. 911– 921. DOI: 10.1016/j.jallcom.2018.03.222. 7. Manokruang S., Vignat F., Museau M., Limousin M. Process parameters effect on weld beads geometry deposited by Wire and Arc Additive Manufacturing (WAAM). Advances on Mechanics, Design Engineering and Manufacturing III. JCM 2020. Springer, 2021, pp. 9–14. DOI: 10.1007/978-3-030-70566-4_3. 8. GrzesikW. Hybrid additive and subtractive manufacturing processes and systems: a review. Journal of Machine Engineering, 2018, vol. 18 (4), pp. 5–24. DOI: 10.5604/01.3001.0012.7629.

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