English to German Tech/Engineering Chemistry; Chem Sci/Eng Electrolysis

Hi again,

This is from the same text as my previous question. Here is the sentence:

At the top of grooves we see a bit of *pitting*. It is really hard to confirm, but it seems that the pitting doesn't affect the chromium layer and is confined in the additional top layers.
Is the surface preparation of the chromium a bit too aggressive?

I found *Lochfraß* and *Grübchenbildung* and I opted for *Lochfraß*, but I am not sure.
TIA