CPM154cm rusting??

[Leatherpunch802]

Hello,
I bought six feet of CPM154cm steel from a supplier I've had good luck with in the past. I profiled a couple knives and started grinding in the bevel, cooling them in water. I noticed some small spots of rust, like you might see on O1. This surprised me, thinking it should be impervious to rust, so I decided to test the steel to see if I was going crazy. I took some gun bluing liquid and put a few drops on the metal and it instantly reacted. Its my understanding this shouldn't ever happen.

Before I contact the supplier I figured I'd check with you guys to see if anyone who knows more about metallurgy could tell me if CPM154cm stainless steel in its annealed state would react to water or gun blue.
Thanks!

 

[Hengelo_77]

It needs to be hardened to be stainless

 

[Jesse Latham]

Stain less not stain free.

 

[Kevin McGovern]

Stainless steel will rust pretty easily until it's hardened. Not as easily as 10xx steels, but surprisingly easily .

 

[Leatherpunch802]

Thanks y'all, I'll keep grinding. I dug deeper on this site and google. sounds like until I harden the chrome is not available and whenever you grind you take off the layer of chrome oxide which protects stainless.