Joining of plastically pre-deformed Q235 steel by MAG welding

This paper investigates the feasibility of welding on a stamped steel part used in the automotive industry. A bending machine was employed to introduce a continuous and incremental deformation (up to 35 % true stain) on Q235 steel plates. Afterwards, Metal Active Gas (MAG) welding process was carried out on the folded plates and the weld toes were positioned respectively in areas of 15 % and 30 % plastic pre-deformation. Non-deformed Q235 steel weldment was prepared as a control sample. The results show that the appropriate welding parameters within the framework of this investigation are 4 mm/s as the speed of the torch, 4.2 m/min as wire-feed speed and 23 V as the welding voltage. In addition, it is found that despite the similarity of the microstructures, the fusion zone (FZ) and partially melted zone (PMZ) on the pre-deformed weld joints are both narrower than the control sample. Different zones are observed along the isotherm.