[TheForge] Re: [TheForge] Re: [TheForge] Re: [TheForg e] Heat Treating 5160 was Welding 5160

Sat Aug 30 23:08:01 2003

Dave:  I have seen failure of coils also.....usually accompanied by BIG
grain growth, result of  having gas or hot coke fire blast strike piece
directly.  For some reason, this seems to happen with springs. maybe due to
lack of refractory elements that retard grain growth.  Another mystery....I
always normalize/anneal.

Grant
----- Original Message ----- 
From: "David E. Smucker" <[email protected]>
To: <[email protected]>
Sent: Saturday, August 30, 2003 11:18 AM
Subject: [TheForge] Re: [TheForge] Re: [TheForge] Heat Treating 5160 was
Welding 5160

> Could be Grant,  But I have watch a number of smiths make quick and dirty
> tooling out of coil springs -- 5160 most likely -- and have them crack
> following heat treat -- with no normalize.  They always blame the "old
> spring -- most like had a crack to start with".  I have had this happen
only
> once and I was cutting corners, no normalize and a water quench.    I've
> even seen a demo with new 5160 -- making a punch and it cracked, again
> didn't take the time to do a least one normalize.   They did temper using
> retained heat in the rest of the part.
>
> Now some of these folks were fast -- made some good money resharping jack
> hammer bits -- they only took one heat to reshape the bit, let it cool to
> the black -- which in effect gives them the normalize and a smaller grain
> size -- and then reheat to critical, quench and draw back (temper) using
> retained heat and the file test and a final quench.  With 100 jack hammer
> bits to resharpen time is money.
>
> All I trying to say is there is a balance in what we do.
>
> Dave Smucker
>
> ----- Original Message ----- 
> From: "gblacksmith" <[email protected]>
> To: <[email protected]>
> Sent: Saturday, August 30, 2003 1:31 PM
> Subject: [TheForge] Re: [TheForge] Heat Treating 5160 was  Welding 5160
>
>
> > Dave:  Maybe the reason they don't need to temper is because they not
> > reached  full hardness.  Grant
> > ----- Original Message ----- 
> > From: "David E. Smucker" <[email protected]>
> > To: <[email protected]>
> > Sent: Friday, August 29, 2003 2:24 PM
> > Subject: [TheForge] Heat Treating 5160 was  Welding 5160
> >
> >
> > > Yep, Chuck -- I don't think you would suggest cryogenic quenching for
a
> > > blacksmith's hot punch -- but I wouldn't think of not requiring it on
> the
> > > purchase of a $ 10,000 five percent chrome cold mill work roll made
from
> > ESR
> > > steel.
> > >
> > > It didn't get talk about much in this series but your earlier point of
> the
> > > need to normalize to refine grain structure is one of the more
important
> > > things that is easy to do and many times skipped by the blacksmith
heat
> > > treating his tools.  In general there are only two things we can do to
> > > reduce grain size -- forging, and normalizing.  We do a lot of
> increasing
> > > grain size by multi heats at high temperature and really should
> normalize
> > > before heat treating.  Jim Batson suggest doing this three times for
> knife
> > > blades -- I would settle for once for most tools, but many times it is
> > just
> > > skipped.  Are we really in that big of a hurry.
> > >
> > > The other one I don't understand is the great desire to NOT TEMPER -- 
it
> > can
> > > be done quickly and safely for almost any tool.  Why leave it out.  At
> the
> > > very least put it in the oven at 350 *F for an hour.  It gives only a
> > small
> > > reduction in hardness and a big increase in toughness.  (And yes it
may
> > well
> > > get tempered in service from use on hot metal, but the time to temper
is
> > > right now, following heat treat.  As you have said many blades have
been
> > > lost by the failure to temper now, saying I do it tomorrow -- but it
is
> > > cracked in the morning.)
> > >
> > > Dave Smucker
> > >
> > > ----- Original Message ----- 
> > > From: "Chuck Robinson" <[email protected]>
> > > To: <[email protected]>
> > > Sent: Friday, August 29, 2003 3:41 PM
> > > Subject: [TheForge] Re: [TheForge] Re: [TheForge] Heat Treating 5160
was
> > > Welding 5160
> > >
> > >
> > > > Right Dave,
> > > > And we haven't even begun to discuss:interrupted quenching,
> > mar-quenching,
> > > > banite quenching, multiple quenching, differential quenching, clay
> > > > quenching, and cryogenic quenching.
> > > > Chuck
> > > >
> > > >
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