Effect of welding parameters on welded steel wire mesh

ABSTRACT Reinforced concrete is the most widely used material in construction industry. Generally concrete is reinforced with ribbed bars. In certain applications, it is desirable to use welded mesh and are used in most reinforced concrete structures (buildings, roads, tunnels and prefabricated components). Welded mesh are generally electrowelded (PW: Projection Welding), where the heat necessary to produce the joint is originated by the resistance that oppose the workpieces to the flow of electric current, under the action of mechanical pressure. This process presents various operational parameters which affect the quality of welded joints and the microstructural evolution that takes place during welding. IRAM-IAS U 500-06 standard establishes the requirements to be met by welded steel mesh. The aim of this work is to study the influence of process parameters on the microstructural evolution and mechanical properties of the joints of welded mesh. ATR 500 M ribbed wires of 4 mm in diameter were welded by PW with different welding parameters. The influence of the welding current, welding time, pressure and prewelded time were evaluated. On welded joints, it was characterized the macro and microstructure, microhardness profiles and pull tests were performed. Comparisons with commercial mesh were made and compliance with the requirements of that standard is verified. A strong effect of time and welding current is observed and optimized procedure was obtained.