A few weeks ago, I accidentally dropped a dip nib (don’t remember what it was, probably an Esterbrook 358) into an open bottle of iron gall ink. I didn’t rescue it and promptly forgot about it. About 2 weeks later I emptied the bottle for a routine cleaning and this terrible corroded nib fell out.. it was completely unrecognizable, eaten up by the ink and practically falling apart in my hands. It took no effort at all to grind it into dust.
I hope this shows just how corrosive iron gall ink is to steel nibs and how important it is to keep nibs clean and to never let it dry on the nibs. Just 2 weeks submerged in a bottle of it and it was practically all eaten up by the ink.