My opinion is that 420HC is plenty rust resistant. I've carried Buck knives with that steel in the heat of the summer. I come home from work with my jeans wet from sweat and never had any corrosion problems with the steel. If it can ride in a sweat soaked pocket all day and not rust, it's good enough for me.
Bead blasted finishes, which I believe is the type of blade finish on your Chive, tend to be more prone to rust regardless of the steel.