OBRABOTKAMETALLOV Vol. 24 No. 2 2022 TECHNOLOGY Methods Materials The materials widely used in welding have been selected for the study: carbon structural steel of commercial quality St3 and deformable non-heat-treatable aluminum and magnesium alloy AMg4. Welding plates were cut from a sheet workpiece 4 mm thick. Filler materials were fi ller wires suitable for welding the selected materials: Sv08Kh2GS wire for St3, ER5356 wire for AMg4. The wire diameter was 0.8 mm. The chemical compositions of the materials and wires are given in Tables 1 and 2. Ta b l e 1 Chemical composition of AMg4 alloy and ER5356 wire Alloy Element Fe Si Mn Cr Ti Cu Be Mg Zn Al % <0.4 <0.4 0.5–0.8 0.05–0.25 0.02–0.1 <0.05 0.0002–0.005 3.8–4.8 <0.2 the rest Filler wire % <0.1 <0.25 0.55 0.12 0.12 – – 5.0 – the rest Ta b l e 2 Chemical composition of steel St3 and wire Sv08Kh2GS Steel Element C Si Mn Ni Cr Cu S P As Fe % 0.14–0.22 0.15–0.3 0.4–0.65 <0.3 <0.3 <0.3 <0.05 <0.04 <0.08 the rest Filler wire % <0.1 0.6–0.85 1.4–1.7 <0.025 1.8–2.2 <0.025 <0.015 <0.013 – the rest Design of experiment and equipment The research was carried out in two stages in accordance with the design given in Fig. 1. The fi rst stage included welding the seam onto plates 4 mm thick and 30 mm wide followed by detecting changes in the structure of the welding zone. The second stage included welding of two plates and tension testing of the joint. The plate length was measured based on the distribution of vibration along it (as described below). To excite vibrations in the weld zone, an ultrasonic rod vibration system comprising a magnetostrictive transducer 6 and waveguide 5 made of titanium alloy was attached to a plate 1 via threaded connection 4. The waveguide diameter was equal to the plate width (30 mm). A UZG 2.0/22 ultrasonic generator with frequency and amplitude adjustment was used to supply power to the vibration system. These functions maintain stable vibrations in conditions of increasing temperature and changing the volume of the plate that occur during welding. Before welding, the plate surface was cleaned using a disc metallic brush and degreased. This was followed by ultrasonic machining and welding. Ultrasound was turned off when the weld joint cooled down to 100 C, so that all phase transformations occurred under the infl uence of vibrations. The weld was obtained by semi-automatic welding in shielding gases. Table 3 lists equipment and welding modes for St3 and AMg4.
RkJQdWJsaXNoZXIy MTk0ODM1