Not really mate you could have anything from mild to high alloy. Best bet if you really want to use weird scrap is try and harden it, heat it up to cherry red quench in oil or water and see if snaps when you bend it. This still wont tell you a great deal about the steel type though just that it can be hardened.If you really want to scavenge material I would suggest files or car springs these are usually fairly simple carbon steels that can be worked into serviceable knife with simple tools and some research here, have a look at what some of the neo-tribal guys here are using and making. But I would suggest your best bet is find a steel supplier and buy some 1084 or similar its pretty cheap and available in all different sizes. Read the stickys here and you should be able to build something you can use.
