Razvoj modificirane robustne varilne naprave za MIG/MAG varjenje visokotrdnostnih jekel (Slovene)

The research results are relevant in the field of high strength steel heat treatment, particularly by gas shielded metal arc welding. The heat input is critical when welding high-strength steel. Thyristor MIG/MAG welding supply with constant sinusoidal pulse enables the droplet transfer of filler material during each pulse and softer welding with minimal spraying and controlled heat input. An important finding is that the heat input should be as low as possible and the welding process is implemented with setting the initial and final level of welding current. These are the reasons why the standard MIG/MAG welding process is most suitable for welding the high strength steel. In addition to this standard MIG/MAG welding process the several other variants of the MIG/MAG welding procedures are important: - MIG/MAG welding with flux-cored wires enables to adjust the chemical composition of weldments; - MIG soldering (ideal for bonding galvanized thin plate); - AC/MIG welding (use of AC welding current, welding of thin plates with wide gap,..) The MIG/MAG welding process is ideal for automation and robotics welding applications. With appearance of the inverter-based welding power sources, impulse welding technology, better welding wire feed mechanisms, and using appropriate shielding gases (for example, mixtures with gas argon), a many improvements of the conventional welding process have occured.

The MIG/MAG welding technology and characteristics of MIG/MAG processes are investigated with the aim to enable the project partner Varstroj, the development of the new series of MIG/MAG welding equipment, which will make possible to realize the advanced welding processes. The welding technologies and manufacture of welding power supplies represent one of major export products for Slovenia. The majority of these product, however, is of a too-low technological level, shown in too low added value, so that they need to be upgraded in the years to come or be replaced by more modern ones. The research results will be presented to a wider professional audience at home and abroad at various congresses and in periodic technical and scientific publications. The beneficiaries are expected a series of new products, i.e. welding power supplies, which will allow the appplications of several new welding methods. The new products in a higher price range are expected to increase competitiveness at foreign markets. Indirectly, the research results will affect also an increase of the quality of high strength steel welded structures.