OBRABOTKAMETALLOV technology Vol. 26 No. 2 2024 with a separation between electrode replacements. The current parameters were the same as in the case of welding the root and filling layers of the seam. On the facing seam, as well as on the filling seam, a fairly large amount of sputtering is visible, which is also a signs of a defect. At the same time, spattering was less than when using electrodes manufactured by “Sudislavsky Welding Materials Plant”, LLC. The flash sputter was removed in preparation for further testing for the mechanical properties of the weld overlaid metal using only an angle grinder. The slag on the facing seam was removed with difficulty using a welder’s hammer, since the impact of an angle grinder on the facing layer of the weld seam is prohibited. At the same time, slag was removed much easier than when using electrodes manufactured by “Sudislavsky Welding Materials Plant”, LLC. Welding a specimen using electrodes produced by ESAB-SVEL The hydrogen index is indicated on the pack in the range from 5 to 10 cm3/100 g (Fig. 6). Note that the mode of calcination of ESAB-SVEL electrodes differs from the mode recommended for calcining electrodes manufactured by “Sudislavsky Welding Materials Plant”, LLC and CJSC “Elektrodnyi zavod”. Fig. 6. Information provided by the manufacturer on the package Fig. 7. Formation of the fingernail after welding after welding with TMU-21U electrodes ESAB-SVEL, St. Petersburg The results of the electrode coating quality tests were examined under a magnifying glass. No chipping of the coating was detected, although partial chipping of the coating with a total length of less than 5 % of the length of the coated part of the electrode is allowed, and also amounted to no more than 20 mm. The “fingernail” (Fig. 7) test was carried out in the same way as with electrodes produced by previous manufacturers; three electrodes were randomly selected from the test package for testing and melted in a vertical position with an angle of inclination of the electrode to the seam of 50–60°. The size of the “fingernail” was measured from the end of the electrode rod to the most distant part of the melted coating. The formation of a “fingernail” from the coating with a size of more than 3 mm and the falling off of pieces of non-melted coating from the rod are signs of a defect. The size of the “fingernail” was within tolerance and was less than 2 mm. During welding of the specimens, the arc burned stably on the root and filling layers of the weld; on the facing seam, unstable burning of the seam was observed, which caused uneven formation of flakes. After identifying the “fingernail” we proceed to welding the specimens. During welding, there was stable arcing in the root and filling layers of the weld; on the facing seam, unstable arcing was observed, which caused uneven formation of flakes.
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