HOT STRESS-STRAIN CURVES OF STEEL DETERMINED BY DIFFERENT KINDS OF DEFORMATION

For the modelling of microstructure development during hot deformation operations as well as for the prediction of deformation loads stress-strain data are required. For this purpose various laboratory deformation techniques are employed. On two steel grades (medium carbon Cr-Mo steel and austenitic Cr-Ni steel) axisymmetric and plane strain compression tests as well as torsion tests were applied with the aim of comparing equivalent stress-strain curves determined by such different deformation tests. The results showed that tor the calculations of deformation loads during multi-deformation industrial operations with rather small individual deformation steps, the choice of laboratory deformation test is not a critical point. Nevertheless, conflicting results are expected by an exact interpretation of stress-strain curves concerning microstructural development by using different testing methods.