Short-term creep behavior of a Cr Mo V hot-work tool steel

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 degrees 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 degrees 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.