Steel stanchions on bicycle forks are a hallmark of cheap crap. Respectable motorcycles have them, but their chrome is comparatively thick and non-porous compared to dreggy bicycle stuff.
So, yeah... it's if not normal, at least predictable. You get what you paid for (or less). You can delay the inevitable by keeping your bike clean and indoors when not riding, and avoiding salty or sandy conditions.
If you would like forks that don't rust, get them with hard anodized or ceramic coated aluminum stanchions.