Prediction of the Thermal Cycles in Dry Hyperbaric GMA Welding Using Partial Differential Heat Transfer Equations

The deepwater hyperbaric GMA welding procedures of sub-sea reparation are evaluated with respect to its behavior under shallow water conditions. In this study, the welding thermal cycles at three different pressure levels were investigated through experiments and simulations. Conventional thermocouple measurement was utilized along with a 2D heat flow model to identify the effect of weld pool shape on the thermal cycle of the weld. A new approach was assumed for considering the effect of third dimension. It was found that increasing the pressure results in minor changes of characteristic weld thermal cycle features. Initially, these variations were considered purely dependent upon the weld pool shape and size. It was found that a number of parameters are competing in different ways, reducing the direct effect of weld pool geometry. Good agreement was observed between simulated and experimental results.