OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 1 2022 Methodology In this work, AISI 316L stainless steel (bulk workpiece) and two coatings (60Cr8TiAl formed by deposition of 1.6 mm fl ux-cored wire and E308L-17 formed by deposition of 2.5 mm electrode) have been studied. The coatings were deposited using Shtorm-LORCH S-series welding machine, (Shtorm, Ekaterinburg, Russia). The chemical compositions of materials, Wt%, according to manufacturers, is shown in Table 1The chemical compositions of materials, Wt%, according to manufacturers, were the following AISI 316L: C ≤ 0.03, Cr 16.5-18.0, Ni 10.0-13.0, Mo 2.0-2.5, Mn ≤ 0.03, P ≤ 0.045, S ≤ 0.03, N ≤ 0.1, Fe balance; 60Cr8TiAl: 0.6 C, 8.0 Cr, 1.5 Al, 1.0 Ti, Fe balance; E308L-17 electrode: 0.04, Cr 17.50, Ni 7.92, Si 0.86, Mn 0.51, Nb 0.30, P 0.03, S 0.01, Fe balance. The 60Cr8TiAl coating was deposited by tungsten inert gas welding (TIG) in the following modes: current 90-110A, voltage 12 V, argon feed rate 12-15 l/min. The E308L-17 coating was deposited by manual metal arc welding (MMA) in the following modes: current 70-75 A, voltage 25 V. The test specimens were prepared in accordance with the requirements of the ASTM G32–10 cavitation erosion test [31], Fig. 2. Surfacing was carried out on specimens of 16 mm and 16 mm high. After that, the specimens were cut out and ground according to Fig. 2. The end part of the specimen 16 mm was subjected to cavitation. a b Fig. 2. Samples for the cavitation tests: a – AISI 316L steel sample, b – the sample with a deposited coating, 1 – deposited layer, 2 – substrate Cavitation erosion was evaluated using an original installation [32], in which the cavitation occurs under the effect of ultrasound on a liquid jet contacting the sample surface, Fig. 3. The constancy of the composition, fl ow pressure and temperature of the liquid is controlled by the feedback algorithm that maintains recycling the liquid. Applying a voltage between the nozzle and the sample contributes to adding an electrochemical effect due to anodic polarization, which increases erosive wear. The voltage value is chosen to be the minimum, at which the effect of erosion acceleration appears. The proposed scheme for cavitation test differs from the standardized one [31] in terms of the location of the sample relative to the water jet as well as the design features mentioned above. This allows speeding up testing, increase the reliability and stability of the results in comparison with analogues [33, 34]. The conditions of carrying out cavitation tests are given in Table 1. The cavitation erosion resistance was evaluated depending on a weight loss criterion. The tests were interrupted at irregular intervals to weigh the test sample. Before and after each interval, the sample was
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