Horst Hill, Andreas Mohr, Daniel Kipp
Many applications in the field of tooling require simultaneous resistance to corrosion and wear. Such demands can be met by a martensitic matrix with embedded carbides if they are harder than the acting abrasive particles and of similar size. A further gain in wear resistance can be achieved by the addition of hard phases into the metal matrix to produce a metal matrix composite (MMC). Ferro-Titanit materials from Deutsche Edelstahlwerke belongs to the group of MMCs.
As a good example, the machines used for underwater pelletizing needs a simultaneous resistance to corrosion and wear. Coming from an extruder unit the melt flow is directed through boreholes of the so-called die plate. After leaving the boreholes the plastic is cut off by rotating knives which are pressed against the die plate. Afterwards, the pellets will be cooled within the water, discharged, collected and dried. Finally, these pellets are used in die casting machines to produce components made out of plastic.
Figure 1: Pelletizing Unit
The die plate is the heart of the pelletizing machine and has to fulfil three important properties:
The new developed and patented material Nikrodur fulfils all of the mentioned requirements and is, therefore, the ideal choice. Based on several tests, Nikrodur shows its strengths in wear resistance, corrosion resistance and thermal conductivity.
Deutsche Edelstahlwerke (DEW) is one of the world’s leading producers and processors of special steel long products and belongs to the Swiss Steel Group. In the three materials groups – engineering steel, tool steel and stainless, acid and heat resistant steel – Deutsche Edelstahlwerke offers international customers a uniquely wide range of product dimensions, from drawn wire with a diameter of 4.5 mm to open-die forgings with a diameter of 1,100 mm. As a partner with technical competence in steel, Deutsche Edelstahlwerke develops innovative, individual special steel solutions for complex high-tech applications and offers services ranging from steelmaking to extensive steel processing and steel finishing.
The newly developed material Nikrodur offers increased wear resistance up to 50%, increased corrosion resistance up to 35% and reduced thermal conductivity of 20% compared to Nikro 128.