Due to the ensuing shift toward adoption of increased levels of scrap during steel production to reduce the carbon footprint, it is essential that the effects of tramp elements entering the produced steel from the scrap are understood. In this context, effects of four major tramp elements (Ni, Cu, Cr, and Mo) on the phase transformation and the microstructure evolution of medium‐manganese steels are studied by theoretical predictions. The results indicate that Cu and Ni are beneficial, whereas Cr and Mo have mixed effects due to the formation of different equilibrium metal carbides. The Cu and Ni concentrations of 0.1–0.5 wt% marginally increase the maximum retained austenite content by 2 vol%. Cr reduces the achievable maximum amount of retained austenite more strongly (decrease by 8 vol% for 0.5 wt% Cr) than Mo (decrease by 4 vol% with 0.5 wt% Mo), and Cr gives a wider processing window for achieving a microstructure with a lower variation than Mo. Combined effects of the elements are to decrease the maximum retained austenite by 8 vol% with lowering of processing temperature by 20 °C. This work provides a guideline for the selection of the optimum processing window of medium‐manganese steels in a circular economy.</jats:p>