Transformation plasticity is considered as a phenomenon limiting the actual stress for any specified strain rate under conditions of phase transformation. A one-dimensional model of a steel bar strained under martensitic transformation is provided. Discussion is limited to a series of accepted assumptions, such as athermal kinetics of martensite transformation, monotonic evolution of temperature and constant transformation plasticity parameter. An equivalent tangent modulus is deduced indicating the decisive parameters influencing the softening modes. The obtained model is utilized together with well-known transformation plasticity laws and martensite transformation kinetics to demonstrate an actual softening of steels under the martensitic transformation.

The possibility to manage stress and strain in hardened parts might be beneficial for a number of inductionhardening applications. The most important of these benefits are the improvement of fatigue strength, avoidance of cracks, and minimization of distortion. An appropriate and powerful way to take the stress and strain into account during the development of a process is to make use of computer simulations. In-house developed and commercial software packages have been coupled to incorporate the electromagnetic task into the calculations. The simulations have been performed followed by analysis of the results. The influences of two different values of quenching intensity, strength of initial material structure, strength of austenite, surface power density-frequency-time combination, and workpiece diameter on the residual stress are studied. The influence of quenching intensity is confirmed by the series of experiments representing the external hardening of a cylinder with eight variations of quenching intensity. Measured by x-rays, the values of surface tangential stress are used as a dataset for verification of the model being used for analyses.