Consolidation of mechanically processed sprayed powder of high-speed steel 10P6M5 by methods of cold, hot and dynamic hot pressing

Introduction. Powdered high-speed steels have a number of advantages over their cast counterparts, including a more finely dispersed microstructure and a more uniform distribution of carbide inclusions in the volume of the material, ensuring their better mechanical properties. However, the production of tools from such steels is technologically difficult due to the poor formability of high-speed steel powders due to their high hardness. To effectively produce high-density work pieces, it is necessary to use static or dynamic hot pressing methods. The aim of the work is to investigate the possibility of using these methods to consolidate sprayed and mechanically activated powder of high-speed steel 10P6M5. Materials and Methods. Watersprayed powder and powder that underwent mechanical activation in a planetary centrifugal mill were used as feedstock. Static hot pressing of the samples was carried out in a graphite cylindrical mold at a temperature of 1000°C at a pressure of 50 MPa and an exposure time of 3 minutes. Dynamic hot pressing was carried out in a cylindrical mold at a temperature of ~ 1250°C with a sealing operation of 150 MJ/m3, the powder was placed in an airtight steel container. A heat treatment cycle (quenching and multiple tempering) was performed for the obtained samples. The hardness and relative density of the samples were measured, and their microstructure was studied by scanning electron microscopy. Results. It was found that the preliminary mechanical activation of the powder has a negligible effect on its compactness by hot pressing methods, however, it contributes to the formation of a more finely dispersed structure of the obtained samples. In DGP, a structure with a smaller average grain size and a more dispersed distribution of carbide particles in the work piece from the processed powder is observed. Resume. 1. The paper presents the results of research on hot pressing and dynamic hot pressing of high-speed steel powders. 2. The research results can be useful in the production of billets from high-speed steel powders.