profiling the edge of steel ribbon

[Plako]

We have a problem with a skiving operation. We cut a profile on to the edge of steel ribbon (.010 by .025 wide) by using carbide inserts mounted in a rigid holder. The desired form for the edge is cut into the inserts using a wire EDM. The wire runs past the skiving insert at 800 ft/min. Right now the inserts are set at a positive rake angle of 2 degrees. Problem is that we can only run them for about 90 minutes or so before they start cratering or eroding away, which of course calls for downtime to change inserts. Heat does not appear to be an issue since we use an external flood coolant.

Is there another material we could use for this skiving tooling?

Any suggestions on increasing or decreasing the rake angle.

Any help would be greatly appreciated!

 

[EdStainless]

The form isn't ground? You use the EDM finish?
I suspect that there is surface damage from the EMD process that is shortening the life. If the surface is slightly rough then metal will want to stick to it. Once that happens it is all downhill.

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Plymouth Tube

 

[TVP]

As Ed already stated, you cannot use the inserts immediately after the EDM process, due the recast layer on the surface. They must have some type of surface finishing process, such as grinding, polishing, micro blasting, etc.