Microstructure evolution simulation in hot rolled DP600 steel during gas metal arc welding

This work investigates the gas metal arc welding (GMAW) process of high strength hot rolled dual phase sheet steel and discusses the modelling techniques. The thermocycles during welding were measured experimentally and simulated with the software tool SimWeld. The evolution of different diffusional transformational phases was simulated based on dilatometer experiments. MICRESS® was used to simulate the change of the microstructure during heating and cooling periods. The significant input parameters include interface mobility and nucleation density. A simple bainite transformation model was added in MICRESS® since it is needed in predicting the microstructure undergoing fast cooling. The simulation results are compared with experimental findings, and good agreement is achieved.

► The thermocycles during GMAW were studied experimentally and numerically.
► Evolution of diffusional transformation was simulated during heating and cooling.
► A simple bainite transformation model was used for fast cooling conditions.
► The simulation results showed good agreement with experimental findings.