Being a railroader, I get the same question at least once a month...will you make me a railroad spike knife. They first expect it for free because of my access to tons of them and then frown when I say they are useless unless you insert a high carbon chunk of billet into it for the cutting edge. NOTHING you find on the tracks can be used for knives except for an occasional spring & they are a total PITA to work with.

Don't be cheap with your time, buy some good "known" knife steel like mentioned above for learning the craft...then experiment as your knowledge grows. Once you think you have the hang of it, try to make a razor...then you have done something!