On Sat, 06 Mar 2004 20:06:59 -0600, "B.B." u wrote:
In article ,
Gary Coffman wrote:
I doubt you'll be able to remove the warp in hardened
1090 by cold working. I suspect you're going to have
to anneal it, straighten it, and reheat treat it.

Can you "wear out" a piece of metal by repeatedly heat treating it,
annealing it, heat treating it, and so on? Or is it something that's
yes for some metals, no for others?

You're going to lose some of the surface to scale every time you
heat it, unless you have a controlled atmosphere furnace. You
have to allow for that when you choose the stock.

If you *overheat* steel, ie bring it to a white heat, you'll burn some
of the carbon out of it, as well as produce a lot more scale. That's
not an issue at normal forging and heat treating temperatures.

Also, if you hold steel above the critical temperature too long,
you'll get grain growth, which weakens it. This can be corrected
by annealing and reheat treating.

Intricate decorative pieces may have 50 or more "heats" involved
in producing them. The metal doesn't "wear out", though as I noted
there will be some losses to scale formation with each heat.

Gary