[TheForge] Super Quenched Dies?

[Carl Tappan]

<Quoth Dave>
Again for low cost tool steel I would use the head of a railroad rail 
(close to a 1080 steel), or a section of leaf spring.  Weld the leaf 
spring to a base of other steel.  Or keep checking around the "junk
yard" there is a lot of 4340 and 4140 out there in lots of items.
<So Spoke Dave>

The concern I have about RR rail is the work hardening; Doesn't it do
that to the extreme from all the Mn? I called a couple of machine shops
today, and one guy thinks he has some 4140 in the size I want kicking
around. I tried just superquenching a piece of the 1018 that I am
thinking about for dies, and the hardness didn't go in far at all. If I
can't get a hold of any good steel, I think I might try the leaf spring
idea. That seems like it should work, barring incompetence on my part.
Thanks,
Carl Tappan