OBRABOTKAMETALLOV Vol. 25 No. 4 2023 technology Down milling is recommended for processing the parts made of the 316L steel produced by laser additive technologies (LAM) [17, 18]. It provides a better surface quality in terms of roughness compared to that of counter-production. Tool wear can be reduced and machining productivity can be increased using ultrasonic vibration milling during down milling [19–23]. At the same time, the work is currently underway to combine additive and subtractive technologies using the same equipment [24]. This improves the manufacturing accuracy, reduces the operating time and tool wear. The importance of determining the optimal processing modes of workpieces obtained by additive wire printing methods is noted in [25]. Moreover, the standard processing modes are reported not to provide optimal results. In general, the authors of [25–28] also suggest that different positions of the workpiece during 3D printing generate different properties during printing. The vertically manufactured workpieces are cooled more slowly than the horizontally located ones. As a result, depending on the workpiece location during printing, its properties will be different. This will also affect the processing modes. Therefore, when assigning subtractive processing modes, it is important to know the workpiece manufacturing specifics. This will directly affect the quality of processing and tool wear. This is especially important for the parts made by electron-beam printing (EBW). The printing blanks using the WAAM method is more widespread due to its low cost. The EBW method produces more precise and critical parts. Such parts should have higher accuracy. Therefore, for workpieces manufactured by the EBW method, it is extremely important to study the features of subsequent retractive processing. An analysis of the literature shows that there are works devoted to the properties of differently oriented printed specimens. Nevertheless, there are practically no works showing how much these changes in properties for differently oriented printed specimens affect the modes of subtractive processing. There are practically no works devoted to the processing of the workpieces printed using the EBW method. There are very few works devoted to the subtractive processing of the workpieces obtained by electronbeam printing. Therefore, the topic of selecting optimal modes of processing the workpieces manufactured using WAAM (wire surfacing) methods is very relevant. The aim of this work is to use the experimental work to determine the patterns of changes in forces when milling the workpieces made of the stainless steel 0.4 % C-13 % Cr, manufactured by electron-beam surfacing. Materials and methods To conduct the research on milling, specimens were obtained using the electron-beam wire surfacing technology. 10 specimens were printed for the research. 5 specimens were used for down milling and 5 specimens underwent up milling. The dimensions of the specimens were 14×70×15 mm (height × width × length). The specimens under study were printed using steel wire, the chemical composition of which is given in Table 1. Ta b l e 1 The chemical composition of martensitic steel C Mn Si Ni Cr P S Fe 0.40 0.49 0.54 0.50 13.1 0.020 0.016 balance Manufacture of the specimens using an electron beam installation The specimens were printed using an electron-beam (EBW) wire surfacing machine. The installation was developed and manufactured at Tomsk Polytechnic University (fig. 1). The accelerating voltage of the EBW installation is 40 kV and it remains unchanged. The current variation range is 0–200 mA. The initial material intended for producing a workpiece using the EBW method is the stainless steel 0.4 % C-13 % Cr wire with a diameter of 1.2 mm. The general scheme for printing the specimens is shown in fig. 2.
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