Using double ellipsoid heat source model for prediction of HAZ grain growth in GTAW of stainless steel 304

The grain growth in HAZ of austenitic stainless steels during welding is an important metallurgical change that affects the mechanical properties. In this study, the finite element simulation of heat transfer in GTAW of stainless steel 304 is investigated using double ellipsoid heat source model. The simulation results are compared with the results obtained from the analytical Rosenthal model and also experimental data. The simulated peak temperatures are close to the experimental results at the measurement points (the maximum relative difference is 10%), while the Rosenthal model has a maximum relative difference of 34%. It is also observed that the simulated weld pool size is also better compatible with the experimental results than the Rosenthal model. Additionally, the calculated grain size based on the simulation results is also more consistent with the experimental data than the Rosenthal model, particularly near the fusion boundary.