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Hot-work tool steels are used for die casting, extrusion molding and drop forging tools and thus are exposed to high temperatures and elevated stresses during application. To get insight into the materials' behavior under those conditions, short-term creep tests are performed at temperatures in the range of 550 – 590 °C and at stress levels ranging from 400 – 750 MPa. A steady-state creep range is not observed. Instead only a minimum strain rate appears. This minimum is followed by an extended tertiary creep range. Based on the observed stress exponent at 590 °C recovery-controlled dislocation creep has been identified as the dominant creep mechanism. During creep carbide coarsening, recovery and recrystallization occur, as observed by scanning electron microscopy and transmission electron microscopy.

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Induction heat treatment facilities have a wide application range for heat treatment of cylindrically shaped materials in the steel processing industry due to their reduced process-time and high throughput. The adjustment of the heat treatment process usually aims at reaching a desired hardness. However, the question arises whether the full potential of the applied material is actually exploited. Therefore, this work systematically investigates the influence of the primary microstructure, austenitisation and tempering conditions to the resulting notch impact energy and flow behaviour of a 50CrMo4 quenched and tempered steel, with normalised and soft-annealed prior microstructures. The heat treatments, performed with a laboratory induction heat treatment facility, show that low austenitising temperatures lead to a distinct yield point with reduced strain hardening, while increasing the tempering heating rate results in the precipitation of smaller carbides and a significant increase in tensile strength. Austenitising needs to be adjusted to the primary microstructure to reach an optimum solution state to exploit the hardness and notch impact energy potential.