Wire EDM effect on heat treated steel

Need to section some samples to confirm induction hardening of a specific area.
Need to confirm my idea that wire EDM will have minimal effect on the Rockwell of my section sample.
Is there a specific referance in some printed material that can be source.

Thanks, you know the paper work has to out weigh the part before it's right.

With 15 years of cutting D2 stamping dies that rockwell around 62, and millions of hits with no ill effects, Id say there is no effect at all on Rockwell values.

With all or most of the new machines there should be no white layer and no damage to the parent material.

TMD

Thanks Metal Doc and CDi, that is what I had always believed but, needed confirmation.

Heat-affected zones

The EDM process uses heat from electrical sparks to cut the material. The sparks create a heat-affected zone that contains a thin layer of recast, also called "white layer." The depth of the heat-affected zone and recast depends upon the power, type of power supply, and the number of skim cuts.

The recast contains a layer of unexpelled molten material. When skim cuts are used, much less energy is applied to the surface, which greatly reduces and practically eliminates the recast layer.

On some machines, the heat-affected zone for the first cut is 0.0015", on the first skim cut it is 0.0003", and on the second skim cut it is 0.0001".

For years, the recast and heat-affected zones have been a concern for the aerospace and aircraft industry. With the improvement of power supplies, these industries increasingly accept work done with wire EDM.

[tooling/incl/99tp.htm]

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Originally published in the November 1999 issue
of Tooling & Production.

I don't have the source to site specifically, but I was doing some researce on 4340 and they recommended re tempering after wire edm to address the Heat Affected Zone, for fatigue strength issues. I found this information on a Alloy Metal Manufactures web site. I did not bookmark it but a search might find it.