Chipping and spalling on the front face of
the die and on the die land were responsible for the defective extruded product. The poor performance of these dies
was attributed to the brittleness of the Stellite 4B in the
powder form using the HIP process and this is justified
by the increased hardness of 65HRc compared to 48HRc
in the as cast condition. Furthermore, cracks were formed
in the stellite region and were arrested by the steel body of
the housing, as illustrated inFig. 7on a cross section of the
used dies.