I test various knife steels (52100, O1, Niolox & 14C28N) for corrosion in water, tomato, onion and ferric chloride. Check out my knives at www.chopknives.com and subscribe to my podcast at www.knifetalk.net #knifemaking #howto
When a steel alloy has atleast 12% chromium you can say its basically rust free - but as speaking of rust free steel there is actually no "rust free steel" at all, it just retards the process of corrosion . It is a play between the alloy components in the steel itself. chromium, copper, mangan, nickel increase the ability to resist corrosion , but they also decrease certain other properties of the alloy when being part of it.
This wasn't true 2 years ago, and it's even less true now. H1, Vanax, LC200N.... Rust free steels that use tiny amounts of carbon but larger amounts of nitrogen, causing nitrides to form as opposed to carbides. Also, contrary to what you read on the internet, the correct way to determine if a steel is "stainless" is the ratio of chromium to carbon. Not a fixed number. Most people would say 14% chromium makes a steel stainless, but that's assuming 1% carbon. For example: ZDP189 has 20% Cr, but stains very easily because it also has 3% carbon; well under the 14:1 ratio that nearly all "stainless" steels aim for. The higher the amount of carbon, the more chromium carbides form. Chromium carbides do nothing to prevent staining. Chromium will only contribute to corrosion resistance when left unbonded with carbon and in solution. TL;DR: You'd be wise to not just parrot back what you read on the internet. Odds are, what you're parroting back was just parroted back by someone that may know even less than you.
Great video, this just goes to show that instead of looking for some ultimate supersteel that will never exist, people should just learn how to properly care for their knives.
Dang, I missed that. I am surprised it stained as much as it did then. Perfect execution on that. I haven't used any stainless in any metal project yet. Knife or welding. Guess it's time to study up...
Thanks for doing the test for us! One thing that left me very curious is this: In order to really tell what permanent affect the various solutions had on the steel, wouldn't it be useful to knock off the surface crud with a scotchbrite and see which steels allowed surface penetration? My guess is that the high carbon blades will show more pitting but I'd really like to know.
Nice test Craig 👍 I made one chefs knife out of O1 for my Dad, and slicing tomatoes for burgers at a BBQ had a much faster effect on the surface of the blade in a much shorter time than you had there, and so you’re absolutely right that exposer to oxygen is key in facilitating the reaction (the blade also had water on it, and consequently light rust,because we weren’t paying attention😂). That’s said the knife preformed well, and Dad still uses it, and says he loves the patina pattern, and that’s all that matters.
Nice. I thought niolox was going to do better for some reason. It would be nice to try some different food grade oils on the steels and see which was better. Run one batch through a dishwasher and so on.
@@CNYKnifeNerd wait, seriously? I didn’t think that 80crv2 is that much corrosion resistant, especially since knife makers call it carbon steel rather than stainless one, like 14c28n manufacture does (12c and 13c too)
Great presentation Craig! Thanks for the great info and your great podcast. If anyone wants to dive deeper into corrosion resistance in kitchen knives, check out Jay Fisher's latest webpage called Food Safety Kitchen and Chef's Knives. You can find the link on his homepage at www.jayfisher.com
