Influence of the Powder Fraction on the Properties of Powder Metallurgical Produced High-speed Steel

The influence of the powder fraction on the properties of the Böhler high speed steel S290 Microclean® was investigated. Therefore, the standard powder was sieved into six different powder fractions which were hipped, rolled/forged, soft annealed and tempered. Microstructure characterizations were made by scanning electron microscope (SEM), x-ray diffractometer and an image analyse software. Next to the estimation of the fracture toughness tensile tests were performed. The investigations indicated that the carbide size distribution was influenced by the powder fraction. However, the different powder size classes showed no effect on the mechanical properties. Though, there was no significant improvement of the mechanical properties by a further particle size reduction of the standard powder at the same production parameters. © 2010, Springer-Verlag.