EDM Blanks

Corrosion Resistance NF

In order to solve the corrosion problem of cemented carbide and avoid the above problem, CERATIZIT and CB CERATIZIT experts collaborated with branded WEDM machine manufacturers to create the new corrosion resistant carbide grades –NF series, in order to increase the stability and corrosion resistance feature of Tungsten Carbide, thus highly improve the tool life of stamping die.
The new NF series corrosion free grades not only can slow down the cobalt depletion rate by a factor of 80, it can also help to increase the stability of cemented carbide during the WEDM and other machining process. Thus it can greatly improve the tool life of the punch and die which is most widely used in blanking and lamination industry. Corrosion resistance concept works in the beginning of grade preparation by mixing the powder with corrosion inhibitor
elements. Once the NF grade carbide contacts with dielectric substance (e.g.water, lubricant etc.), a thin layer of oxide will form on the surface of the carbide for protection (see figure). It will isolate the carbide with the outside environment and thus preventing it from further corrosion. Because the corrosion inhibitor elements are mixed with the powder, so the protection is sustainable, and continuous throughout the whole machinning processing.

The NF Grade has the below advantages:
1. More able to sustain extreme dielectric medium condition in WEDM process which help to cost down filtration cost.
2. Can avoid extra corrosion prevention measure which reduce the poor affect on the machined surface.
3. Maintain good surface quality after machining that avoid sticking during stamping, thus increase tool life.