Stripping nickel from nichrome

I wish to remove a thin (<4nm) nickel layer which has been evaporated onto nichrome with minimal loss of the underlying nichrome. Any suggestions for this etch would be very much appreciated.

There is enough chrome in nichrome to withstand a 50% nitric acid dip to remove the nickel which is relatively thin. Obviously, it needs attention during the strip till you get a feel for it. Dissolved iron or copper will accellerate the strip and tend to cause pitting when the level reaches some magic number.

1. Can Nichrome wire breakdown when heating is applied

2. Is there any gasses created by nichrome when heating.

I would appreciate any information or help with my nichrome wire troubles

Thank You,