To do it right you will probably have to know what formulation of steel you are dealing with, I believe. Is it air hardening, or plain carbon steel that could be oil quenched? Only the manufacturer of the blade would be likely to know. There might be some info on the internet about a treatment you could use that would provide adequate results but its still kind of a crap shoot unless you know for sure what the material is exactly. That will make a difference in the equipment you would need and temperatures that you will need to heat to and soak times if you really want to be in control of the results. I always use known material for my projects and I have a friend with an oven that can do pretty precise heat treating for me based on the type of steel I am using. I understand how it works I just don't have my own oven. Hopefully someone else can give you some better advice. I have not tried saw blades of any kind.