Physically based modelling of phase transformations during welding of low-carbon steel

Austenitisation and reversion to ferrite in the heat affected zone (HAZ) of AISI1005 welded steel have been simulated using physically based derivations for interface mobility and the driving force for transformation in a multiphase phase-field methodology. The nucleation and growth of both austenite upon heating and ferrite upon cooling are presented. Pearlite is modelled as a pseudo-homogeneous phase to drastically reduce computational costs. Comparison of calculated phase fractions with in situ real-time synchrotron measurements in the literature yields a good agreement, both in temporal and spatial aspects.