Abstract
Hot cracking in welding is a complex phenomena due to coupling between process, metallurgy and mechanical loading. In this paper, a coupled approach that integrates microstructural prediction based on the process simulation and criteria at the microstructural scale is proposed. The criteria is based on some development of Rappaz et al [1] and takes into account the influences of grain morphology, mechanical and thermal fields induced by welding, on hot cracking. To integrate all factors influencing hot cracking, a methodology is developed that couples process simulation, simple microstructural prediction and criteria along columnar grains. The criteria based on the microstructure behavior is able to predict crack onset location in columnar grains zones.