I haven't stumbled on corrosion as a problem with my knives, but, they are all of reasonably decent quality stainless. I have had corrosion problems with axes and mauls, but, usually I find that surface rust will get scraped off after splitting a few logs.

One problem I had with folders that I used to clean fish or dress game was the, ummm, how to say this nicely, nasty gross stuff that grows inside the slot if I am not good about cleaning them soon after doing my work. One time, I went out to my boat and thought something had died inside it. My Buck folder had a bunch of green and white slime growing out of it after it was used to clean a cooler full of striped bass on the boat, and then sat out on the boat for over a week under the canvas on some nice hot days. It looked like a creature from a cheap horror flick. I'm glad I found it before my wife came on the boat, that could have been ugly.

I've been better about doing a good fresh water rinse after use ever since...