I don't know any thing about making knives or blades. so please let me know if these won't work. I just replaced the knife blades in a few large (Vermeer industrial) log chippers. I saved the old ones. I want nothing for the old ones, I just hate to recycle them if they can be used to make blades. Let me know if there is any interest.
Sure they can be used for knifes. But the problem is knowing how to heat treat them without knowing what the steel is. A maker would have to use trial and error with it to see what HT works best.