Can electroplating improve the texture of a steel ball bearing so that it will have a smooth surface free of scratches even a few microns wide? I'm trying to find a way to remove scratches (about 10 microns wide) from carbon-steel electrodes and have recently started looking into electroplating. I have already ruled out electropolishing and using rotary/vibratory tumblers.
In general, this doesn't really work. To level a surface by electrodeposition, material would have to deposit in recesses in the surface faster than it does onto surface features that stick out. Normally, the opposite occurs because things that stick out are more accessible for diffusion. Electropolishing works because it's doing the opposite process in solutions viscous enough to enhance the differences in diffusion.
Not to say that it's impossible to level surfaces by electrodeposition. It's been known for a long time that certain additives to plating baths can change the deposition selectivity to this end. However, the mechanisms behind these effects are not well known and it seems to be pretty difficult to achieve consistently. Also, you won't be able to electrodeposit carbon steel, so you would have some other metal on the surface, which may or may not adhere well. I wasn't able to find any specific method for carbon steel—electropolishing seems to be much more common.