Eh. I'm kind of thinking a judgment call needs to be made here as to whether you want to use this knife, or keep it looking great. Any knife you actually use will get scratched and patinated, there's just no way around this unless you continually polish it. Which means you'd be spending a lot of blade material just to keep it looking shiny.

S7 is not a stainless steel, and it will corrode readily if not cleaned promptly (within minutes of use in acidic environments). In my experience it doesn't corrode any worse than expected for a tool steel. Which is why you'll notice that 99% of kitchen cutlery is stainless.

A patina does not significantly affect the knife's mechanical integrity: yes, it is a form of rust, but it is "good rust", which forms a protective layer on the metal that stops further oxides from forming. We have chisels that are over a hundred years old and are completely dark with patina, and they are still solid and sharp. "Bad rust" is orange and powdery, and will just keep getting worse.

I suppose from a food preparation standpoint, patina is not a good thing, but I'd just use the scotchbrite pads and get rid of it. And accept whatever happens to the finish. If it was a user anyway. And if it was a showpiece I wouldn't use it to cut up my steak.

<img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />