Tempering and Intercritical Annealing of Air‐Hardening 4 wt% Medium Manganese Steels

The mechanical properties after tempering and intercritical annealing of medium manganese steels with 4 wt% Mn for forging applications are presented. After subsequent air cooling, heat treatments were performed, specifically from 250 450 °C between 600 675 °C. Tensile properties, Charpy V-notch impact toughness, hardness determined compared microstructural features characterized by metallography synchrotron measurements, leading to the classification six different treatment stages steels. Furthermore, effects alloying additions (boron 0.0016–0.0057 wt%, molybdenum 0.2 aluminum 0.5 wt%) discussed respect properties. It is shown that boron increases toughness more effectively in regime, while alloyed samples exhibit higher annealing. Most materials states follow inverse relationship strength, show a superior tempering.