Influence of simulation methods of temperature distribution on thermal and metallurgical characteristics in GMA welding

A thermal metallurgical CFD-based mass and heat transfer (MHT) analysis was compared with a FEM-based conductive heat transfer (CHT) analysis and a CHT with element activation and deactivation scheme (CHTE) analysis of gas metal arc welding process for the same process conditions. To evaluate the validity of each thermal analysis method, experimental results were also obtained. The CFD-based MHT analysis resulted in the best approximation in the validated thermal and metallurgical results with the vast computation time. The FEM-based CHT and CHTE analyses required very short computational time and showed appropriate agreement in results. The more highly concentrated martensite fraction in the fusion-zone of the CHT analysis result was influenced by the relatively lower temperature history and the faster cooling rate, while the more concentrated martensite fraction in the heat affected zone and the tempered zone of the CHTE analysis result was influenced by the relatively higher temperature history.