Open AccessConstitutive modelling of Usibor® 1500 sheets after intercritical quenching
Author(s) -
Mohammad Shirinzadeh Dastgiri,
Ravi A. Thakkar,
Jun Shi,
Iman Sari Sarraf,
D. E. Green
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1157/1/012071
Subject(s) - materials science , quenching (fluorescence) , ultimate tensile strength , volume fraction , strain rate , hardening (computing) , strain hardening exponent , deformation (meteorology) , constitutive equation , composite material , metallurgy , thermodynamics , finite element method , optics , physics , layer (electronics) , fluorescence
In this study, 0.9 and 1.8 mm thick Usibor® 1500 sheets were subjected to intercritical quenching by heating to 760-930°C and quenching at a controlled rate. The tensile behavior of as-quenched Usibor® 1500 was experimentally obtained using uniaxial tension tests at strain rates ranging from 0.001 to 0.25 s −1 . The constants in the hardening models, including Johnson-Cook, were optimized using a Genetic algorithm and linear regression for each condition at each strain rate. Then, these models were numerically modified to account for heat treatment dependency. Uniaxial tensile tests were simulated using the fitted models and compared to experimental flow curves and strain distribution maps to determine the accuracy of the prediction of each model. Optical microscopy was used to determine the volume fraction of each phase using image processing tools and these characteristics were used to explain the behavior of Usibor® 1500 after intercritical quenching. It was found that intercritical quenching process parameters determine the distribution and morphology of each phase and consequently the range of mechanical properties. This model can be used to simulate the deformation of hot-stamped components with tailored properties produced under controlled austenitization.