IMPROVING THE PREDICTION ACCURACY OF KEYHOLE ESTABLISHMENT TIME IN PLASMA ARC WELDING

Accurate prediction of both the keyhole establishment time and dimensions is of great significance for optimizing the process parameters in plasma arc welding. In this study, appropriate modifications of both heat source and plasma arc pressure models are made to improve the calculation accuracy of the keyhole evolution. The partition fractions of the combined heat source and distribution of the plasma arc pressure on the keyhole wall are transiently adjusted with the variation of the keyhole depth at each time step. A vision sensor is employed to detect the key-holing process for validating the simulation results. The prediction accuracy of the keyhole establishment time is greatly improved.