Experimental investigation on resistance spot welding of galvannealed HSLA steel

A systematic variation of the parameters involved in the spot welding by electrical resistance of galvannealed strips was carried out on samples from a 2 mm thickness galvannealed high strength low alloy steel strip used for automotive applications. The varied parameters in the present study were welding current, welding time, holding time after welding and number of welding pulses, while the dimensions and characteristics of the electrodes and the applied force during welding were kept constant. The wear of the electrodes is important, however it was not the aim of the present study, therefore it was not taken into account. The experimental results were analysed to evaluate the influence of the various parameters on diverse characteristics of the welded bead. It was possible to determine the optimal operational conditions for this particular type of material.