Coupled modelling of thermo-metallurgical processes during quenching of an RPV steel

A coupled FEM model for predicting the thermo-metallurgical processes occurring during quenching of reactor pressure vessel (RPV) steel has been developed. Model considers coupling between thermal and metallurgical process occurring while quenching. A finite element method (FEM) code based on python programming language has been developed to model simultaneous thermal and metallurgical processes occurring during quenching. Thermal processes such as convective and conductive heat transfer were modelled based on usual heat transfer equations, while metallurgical processes such as decomposition of austenite into various constituent phases (i.e. ferrite, pearlite, bainite and martensite) were modelled using various models already available in published literature for predicting the time-temperature-transformation (TTT) diagram. The coupled FEM model was validated by performing Jominy end quench test and comparing the measured and predicted hardness values across the length of the test specimen. (author)