No. It only works on bare steel or iron.
There is a nickel blackener product at
http://www.caswellplating.com/aids/metal.htm
Black & Brown Oxidizer
Blackens silver and nickel and browns copper and brass. Mix 15% concentrate with 85% water. Use as a dip at room temperature.
PROD A313 Black & Brown Oxidizer 16 fl oz $19.00