AN ATTEMPT TO INCORPORATE THE EFFECT OF MICROSTRUCTURE ON THE MACROSCALE SIMULATION OF HEAT TRANSFER DURING HEAT TREATMENT IN MULTI COMPONENT DUAL PHASE STEEL
Dual phase steel is one of the future materials for automobile industry, as it shows a combination of high strength and adequate formability. Studies have shown that it has the potential to occupy up to 80% of the total weight of a car. Residual stress during heat treatments is one of the issues that need to be studied in dual phase steel and computational simulations can help in reducing the experimental trials required for such a study. The heat transfer simulation in such a material is challenging, as it involves phase transformation at the microscale. In the present work, an attempt is made to incorporate the effect of phase transformation at the microscale while simulating the macroscale heat transfer and consequent residual stress. A novel and simple flat geometry is chosen for study that helps in easy measurement of residual stresses. The geometry is a rectangular strip with an elliptical hole and the role played by the angle of elliptical hole on residual stress prediction is discussed. Finite Element simulation of the heat transfer and the subsequent residual stress is performed using the commercial software Simufact Forming®. The effect of microscale phase transformations on the residual stress was considered during the software simulations. These simulations are validated using physical simulations in Gleeble® and measurement of macroscale residual stress with X-Ray diffraction technique.