Quantification of uncertainties in grain size predictions of a microstructure-based flow stress model and application to gear wheel forging

For reliable process design, full knowledge of the possible spread of the predicted target values such as grain size is desirable. In real production the spread of final product properties is caused by uncertainties in the processing conditions and the material behavior. This paper proposes a strategy which allows for incorporating the material behaviors uncertainties in a microstructure model. This model is applied to the design of a hot-forging process. It is shown that the probability distribution of the grain size value is asymmetric and predicts occurrences of grain sizes with a large deviation from the most probable grain size.