Effect of Welding Current and Time on Tensile-Peel Loading in Resistance Spot Welding of SPA-H Steel Sheets Used in Railway Vehicles

This paper presents an experimental study on resistance spot welding of SPA-H weathering steel sheets used in side wall and roof application of rail vehicle bodies. SPA-H steel sheets having 2.3 mm thicknesses were joined by using resistance spot welding as lap joint. A timer and current controlled resistance spot welding machine having 120 kVA capacity and a pneumatic application mechanism with a single lever was used to prepare the specimens. Welding periods were chosen as 10, 15, 20, 25, and 30 periods (1 period =0.02 s) and also welding currents were increased from 6 kA up to 11 kA by rise of 0.5 kA. The electrode force was kept constant at 4 kN. The prepared welding specimens were exposed to tensile-peel test and the obtained results were supported by diagrams and, finally, appropriate welding current and time were advised to the users.