Microstructure Evolution During Quench and Temper of Large Forged Steels

The heat treatment of large forged steels involves complex phase transformations that are strongly influenced by prior deformation and the initial microstructure. However, most existing data are based on isothermal conditions without deformation, which do not accurately represent industrial open-die forging processes.

This Master’s project focuses on the experimental study of microstructure evolution during quenching and tempering (Q&T) of forged steels. Particular attention will be given to retained austenite decomposition, the formation of transformation products, and carbide precipitation. Using high-resolution dilatometry and controlled thermal cycles, the student will investigate how prior deformation and thermal history affect phase transformation behavior. Microstructural characterization using optical and electron microscopy will be conducted to quantify phase fractions, carbide morphology, and microstructural refinement.

The results will provide essential data for understanding phase evolution during industrial heat treatment and will contribute to the development of improved transformation databases and processing guidelines.