Model for inclusion formation in low alloy steel welds

Oxide inclusion formation in low alloy steel welds is described with a model as a function of weld metal composition and process parameters. The model was developed by coupling thermodynamic and kinetic considerations. Thermodynamic calculations considered the effect of the alloying elements and kinetic equations allowed, describing oxide formation during weld cooling. The model showed that weld cooling rate influences the inclusion characteristics and therefore must be taken into consideration. This inclusion model is capable of predicting the composition, size, number density, and oxidation sequence of inclusions and was verified with published data. The inclusion model was coupled with numerical heat transfer and fluid flow models to extend the model to a wide range of welding process conditions.