Finite Element Modeling of Immersion Route Effect on Macroscopic Distortion during Quenching of Long Steel Components

During quenching, long steel components (such as leaf-springs) are more prone to macroscopic distortion, due to a combination of thermal and transformations stresses operating through a relatively thin cross-section. In the present study, a comparison between two different immersion routes (from the distal ends and from the long edge) is analyzed. Several key parameters such as initial temperatures for both the component and the quenching medium, as well as boundary conditions such as the heat transfer coefficient, were calculated from experiments. Transformation kinetics for three different austenitic grain sizes were simulated using JMatPro and validated using quench dilatometry. A three-dimensional, fully-coupled finite element modelling of quenching was developed in Deform 3D. The results between the two immersion routes are discussed in terms of macroscopic distortion and transformed martensite volume fractions. The results show that quenching from the side of long components greatly reduces the martensite volume fraction scatter through the component volume, thus limiting the macroscopic distortion, regardless of the austenite grain size.