The influence of technological parameters on the formation of a wall bead during multi-pass welding in shielding gases

High-quality welding in vital metal structures, such as bridges, machinery, pipes, etc., imposes strict limitations on the power supply per unit length. In the case of multi-pass welding, the buildup of heat transfer to the base metal in the area, where the filler metal and the edge fuse together, increases the possibility of faulty fusion. To control the quality of welding, analytical relationships between the primary and secondary welding parameters and the base metal penetration depth under the flawless wall bead formation are required. The method of mathematical planning of the full factorial experiment was used to derive analytical dependences of the wall bead cross-section area and the total thermal efficiency of the welding process on the groove angle, electrode position in the grooving, and the welding speed. The most significant parameters affecting the formation of the wall bead without faulty fusion are determined. For a given welding current, voltage, and electrode diameter, the input data include the position of the electrode in the grooving and the welding speed. The study showed that shifting the electrode to the edge increases the heat transfer to the base metal and, consequently, increases the efficiency and quality of the welding process. Increasing the welding speed to a certain value increases the penetration depth due to the decrease of a liquid layer thickness under the arc and, therefore, improves the efficiency of the welding process and the weld quality.

References

[1] Cerjak H. Mathematical Modelling of Weld Phenomena as a Tool of Modern Welding Technology. Welding International. 2001, vol. 15, no. 8, pp. 637—644.

[2] Sas A.V., Gladkov E.A. Tekhnologicheskii protsess svarki kak ob"ekt v ASU [Welding procedure as an object in ACS]. Izvestiya Vysshikh Uchebnykh Zavedenii. Mashinostroenie [Proceedings of Higher Educational Institutions. Маchine Building]. 1983, no. 8, pp. 144—146.

[3] Murugan S., Kumar P.V., Raj B., Bose M.S.C. Temperature distribution during multipass welding of plates. International Journal of Pressure Vessels and Piping.1998, vol. 75, no. 12, pp. 891—905.

[4] Berezovskii B.M. Matematicheskie modeli dugovoi svarki [Mathemat ical models of arc welding]. In 3 vol . Vol . 2. Matematicheskoe modelirovanie i optimizatsiia formirovaniia razlichnykh tipov svarnykh shvov [Mathematical modeling and optimization of the formation of different types of welds]. Cheliabinsk, SUSU publ., 2003. 601 p.

[5] Chernyshov G.G., Pankov V.V., Markushevich I.S. Vliianie parametrov rezhima na formirovanie pristenochnogo valika pri svarke v glubokuiu razdelku [The influence of mode parameters on the formation of the parietal roller when welding in a deep butchering]. Svarochnoe Proizvodstvo [Welding International]. 1984, no. 12, pp. 14—16.

[6] Rakhmatullin T.A., Sholokhov M.A., Buzorina D.S. Problemy vnedreniia zauzhennykh razdelok pri svarke korpusnykh<неиkonstruktsii spetsial’noi tekhniki [Problems of narrow gaps welding of special engineering constructions]. Izvestiya Vysshikh Uchebnykh Zavedenii. Mashinostroenie [Proceedings of Higher Educational Institutions. Маchine Building]. 2012, no. 4, pp. 64—66.

[7] Cho S.-H., Kim J.-W. Thermal analysis of horizontal fillet joints by considering bead shape in gas metal arc welding. Science and Technology of Welding & Joining. 2001, vol. 6, no. 4. pp. 220—224.

[8] Erokhin A.A. Osnovy svarki plavleniem. Fiziko-khimicheskie zakonomernosti [Fundamentals of fusion welding. Physical and chemical laws]. Moscow, Mashinostroenie publ., 1973. 448 p.

[9] Sholokhov M.A., Os’kin I.E., Erofeev V.A., Poloskov S.I. Raspredelenie teplovoi moshchnos t i dugi pr i svarke plaviashchimsia elektrodom v shchelevuiu razdelku [Arc Heat Power Distribution under Arc Narrow Groove Consumable ElectrodeWelding]. Svarka i Diagnostika [Welding and Diagnostics]. 2012, no. 4, pp. 18–23.

[10] Korolev N.V. Raschety teplovykh protsessov pri svarke, naplavke i termicheskoi rezke [Calculations of thermal processes in welding, thermal cutting and surfacing]. Ekaterinburg, UGTU publ., 1996. 156 p.

[11] Konovalov A.V., Nerovnyi V.M., Kurkin A.S.,Makarov Je.L. Teoriia svarochnykh protsessov [The theory of welding processes]. Moscow, Bauman Press, 2007. 752 p.