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The article presents the development of a gas-metal-arc welding technology with spin-arc and weaving facilities, for 15 mm thick plates of the steel S355J2+N, according to EN 10025-3: 2019, for shipbuilding and harbor structures construction.The filler metal is the manganese-silicon-alloyed solid wire, type SG-3, according to EN ISO 14341:2020. Shielding gas is mixture CORGON 18/82, type M21, according to EN ISO 14175:2008.The modular drive system MDS-1, manufactured by the company BUG-O Systems, of USA was used. Among other main components, it has a linear weaver unit and a weaver control module.The welding source is the Inverter MIG 300 A type, manufactured by Mahe GmbH, Germany.This welding source is connected with both a spin-arc module and a welding gun, made by the company WeldRevolution of USA. This spin-arc-weaving technology is intended to reduce the welding process duration, filler metal and energy consumption, respectively to increase the productivity by means of both the spin-arc and weaving features of the combined welding equipment.The sizes of the two plates for the welding test piece are: length 370 mm; width 200 mm; thickness 15 mm, I groove with 8 mm gap. This narrow groove preparation is also expected to have a contribution to the reduction of the necessary filler material.The parameter ranges are as follows: arc voltage Ua = 21.7- 23.5 V; welding current Is = 183- 225 A; wire advance speed ve = 6.5- 7.2 m/min; shielding gas flow rate fg = 20.5- 22.0 liters/min; welding speed vs = 20 - 35 cm/min; spinning diameter range ds = 1 - 8 mm, selected diameter dr = 3 mm (3 divisions); rotational speed of the spin-arc vsa = 1500 rotations/min, selected from the range 750- 7500 rotations/min; angular weaving mode; weaving speed (frequency) vp = 2.5 – 5.0 divisions; weaving amplitude ap = 1 – 2 divisions; dwell time tf = 2.0 divisions.After the execution of each layer, the appearance is adequate. No defects or imperfections are found. On ultrasonic examination, the results are adequate. Metallographic examination, tensile tests and Charpy V impact tests have accepted results.The conclusions describe the adequate results obtained, regarding the ranges of the spin-arc and weaving parameters. Possible applications of the S355J2+N steel are recommended.The references cite articles related to welding of ship components, including some spin-arc and weaving equipment. |
