On Apr 4, 10:03*pm, "Ed Huntress" wrote:
"Dar" wrote in message

...





Howdy folks,
Anybody familiar with annealing 0-1 ?. Lately the flat stock I've been
getting is harder than normal , so to test my theory about that being
caused at least significantly by the condition of the steel as opposed
to alloying variances, I annealed a batch of die plates the other
day .
I was right *about that and my guess is that the mill is cutting mfg
costs by not fully annealing the stock that the flat-grinders are
being supplied with. According to data from Diehl Steel, the slow
cooling should take place at 35 deg F max . per hour from 1475 deg to
1110 deg, which takes roughly... *a whole freakin day !. Regardless of
why the steel is harder than normal, my concern is about degradation
that may occur *from the steel spending so much time at elevated
temps. I wrapped my parts in ss foil and that did keep them clean, and
I am assuming that since these are the directions given for annealing,
that it's safe to actually do it; that the steel does maintain it's
"hardenability integrity " through the process of annealing and
subsequent hardening *after cold working.

Input?.

Thanks,

DS

The steel should harden with no problem. Some may question whether you'll
have grain growth as a result of the slow cooling, but, IIRC, that shouldn't
be a problem because it's below the transition temperature for the entire
time. Grain growth wouldn't harm hardenability, but it would harm toughness.

In any case, I think anything that happens to the grain is going to be upset
when you heat it above the transition temp again to re-harden it, anyway.
Considering how careful you're being with the annealing, it ought to be OK..

I've hardened plenty of oil-hardening stock but I don't recall ever
annealing it, so I'm speaking from theory rather than experience.

--
Ed Huntress- Hide quoted text -

- Show quoted text -

The thing in the back of my mind I read somewhere is that carbon can
leach
out at high temps , and it might detriorate the steel and leave it
less tough
or more fragile than it otherwise would after hardening and
tempering . But
it sounds like I'll be ok. Thanks,
DS