Since about 1999 all EKI knives have been coated. Either Black-T, Green-T (no longer an option), Chromium Nitrate (one special run), or Hard Chromed. In 1997 and 1998 uncoated Satin and Bead Blasted finishes were an option.
154CM is a Stainless Steel, but even Stainless Steels oxidize, just at a slower rate.
The HC "Satin" blades are all but impurvious to oxidation. Living in Florida, in and around Salt Water constantly, I can tell you that I prefer the Hard Chromed blades for my carry knives.
I have had the sharpened (uncoated) edge on a couple of Commanders collect surface rust. Simply swiping the edge with Scotchbrite instantly removes it. But the HC remains hard as nails.
No, the HC coating does not come off. Matter of fact, there have been several attempts by folks here to remove the HC coating and Satin finish the knives. Most ended badly.

It's damn tough stuff.
EKI is currectly offering special runs of "Collector Grade" knives in true Satin (uncoated) finishs.
Personally, I'd like to see real Satin become an option in the C/P shop.
Hope that helps
John