Zinc coatings on stainless steel

[whitrabt]

Hello!

Dear sirs, I have a question on painting!
I come across a lot of coating and painting specs which forbid the use of zinc rich coatings on stainless steel. Googling has shown that the reason is because of liquid metal embrittlement of the stainless steel at temperatures over 400 degrees C when zinc starts to melt, but this does not explain why zinc is forbidden for all temperatures.
I'm guessing there are other reasons that I don't know about since this requirement is quite common, or is it one of those "I don't know why but I'll put it in the spec anyway cos everyone is doing it" kinda thing?

Any help would be appreciated! Thanks!

[suphonchai]

when the proper temp , the zince will melt with Cr => zince-carbride and then Cr % will reduce & less the resitance corrosion.