steel and iron type metals have a chance of developing rust if left in humid atmospheres. how about cobalt steel
I have had good experiences with oxidizing stainless steel (316
type) after a medium bead blast surface has been applied, this holds
up extremely well if the oxidized surface is below the wearing
surface. You will not experience rusting with this alloy of
stainless.
More info can be found in previous post -
This does not address the issue of sizing a stainless ring with gold
around it, but it is one of the blackest surfaces I can achieve with
stainless that is comparable to oxidized silver.
P@