Abstract: High temperature failure tests of a commercially produced 15V38 grade steel (0.37% C, 1.37% Mn, 0.56% Si, 0.13% Cr, 0.09% V) were studied in the cast and hot-rolled condition to deliver a material model. Mechanical testing was performed using a hydraulic load frame adapted to perform tensile tests at different temperatures (up to 1300oC) and different strain-rates (up to 20 s -1 ). Plastic flow behavior and the strain at failure of the steel were approximated using the Johnson-Cook Strength and the Johnson-Cook Failure models. Hot-rolled material shows more consistent strength and failure data as compared to the as-cast material. The experimental coefficients of these material models were implemented in ANSYS-AUTODYN FEM to replicate the tensile experiments. The accuracy of each test curve was determined by comparing the experimental data with the simulated results. It was found that FEM simulation with these two Johnson-Cook models predicts well the deformation behavior of the tested steel during the tensile load at studied range of strain-rates and temperatures. These models can be implemented to simulate thermomechanical deformation during hot rolling to predict possible defects.
Authors: M.F. Buchely, D.C. Van Aken, R.J. O’Malley, S. Lekakh, and K. Chandrashekhara
Keywords: Finite-Element Simulation, Hot Metal Rolling, Johnson-Cook Model, Mechanical Characterization