Methodology for predicting the angular distortion in multi-pass butt-joint welding

The study was developed based on experimental evidences, by analyzing the behavior of angular distortion along the passes performed. The investigation involved ASTM A36 structural steel Plates 16 and 19 mm thick multi-pass butt-welded (V-groove) by GMAW process. The work was divided into three main groups. In each of them, experiments were performed using four different heat inputs varying between 0.6 kJ/mm and 2.5 kJ/mm. Three analytical equations were obtained for each group based on the analysis inferred about the distortion results from each experiment. The equations were used to develop a methodology for prediction of angular distortion. Three analytical models were defined and compared among themselves in order to verify the equivalence between them. One of the models obtained from one single experiment (the one that used the lowest heat input from its group) was successful on predicting angular distortion. The model allows predicting the distortion for a defined interval of heat input and number of passes within the domain in which the analytical model is valid.