Influence of wire electrode coatings on the mechanical-technological weld seam and process properties

Funding: DFG

Duration: 08/18 - 08/21

The efficient use of resources and energy is the focus of research today. This results in the objective of this DFG project, how single or multilayer thin film systems on solid wire electrodes in MSG welding influence the welding process and the mechanical-technological properties of the weld metal of welded joints, mainly of unalloyed and low-alloyed steels. Therefore the effects of different elements on the welding wire electrode are investigated and characterized. The basis is the identification, understanding and application of the effects which change the mechanical properties (strength, elongation, toughness, etc.) as well as process properties (arc stability, drop transfer, molten pool dynamics, etc.). The wire electrode shall be coated with metallic as well as non-metallic coatings to investigate a wide range of effects caused by different accompanying elements.

The preliminary investigations show that the welding behaviour and the mechanical-technological properties of the material are strongly dependent on the coating systems on the wire electrode. A striking feature here is the significant reduction in elongation at break. This problem is to be solved in the future by adding nickel, so that solid wire electrodes with higher yield strengths can be produced without reducing the forming capacity.

Based on a fine-grained steel S700MC, mathematical correlations between coating thickness and the influence of various process variables are to be established. This model shall serve as a basis for other base materials. In order to demonstrate the potential of this project, a coating system is to be developed, taking into account the influencing factors for uniform penetration with high arc stability, which simultaneously shows an increase in strength and toughness values.