[TheForge] quench questions

[David E. Smucker]

I don't want to speak for Chuck here -- and I expect we will hear from 
him -- but I would point out that Chuck's anvils are not A36.  I don't 
remember what they are but they have some reasonable (and controlled) level 
of alloy content.  If I remember right they were surplus material from some 
major manufacturing operations.  They are made from "square stock" about 6 x 
6 inches or maybe it is 5 x 5 inches with rounded corners -- typical for 
large square stock from the rolling process.

Using "Rapid Quench" -- my name for super quench -- that is just what Chuck 
is getting -- a high heat removal rate -- and with the mass of his anvils it 
cause no problems.  This is very common process in industrial heat treating 
of large parts.  Steels that we would consider Air Hardening are if fact 
quenched with high force water sprays because with the large mass this is 
what is required to give the correct quench rate.  Some tools steel 
manufactures who shops I have be in use this process for making very large 
die blocks for heavy press work -- these blocks weigh tons.  Similar process 
are used in some heat treating of large forged or cast rolls for rolling 
mills.

My whole point is that it is the rate of quench for any given steel that is 
important -- for small sections of A36 "Rapid Quench" works to generate some 
hardening.  You will get less in true mild steel such as 1020 and in very 
low carbon steel such as 1008 you will get next to none.  The same "Rapid 
Quench" on a heavy section of A36 will not produce the same hardening to any 
depth because you just can cool the mass of steel fast enough.  An example 
in the other directions is I have some 7/8 dia 4340 stock which would 
normally be consider an oil hardening steel -- yet this steel will get hard 
enough if just air cooled in a thin section (say 1/2 dia) after forging to 
take the teeth off my band saw -- done that.

I from the school of "no magic" with Rapid Quench (other wise know as super 
quench) it is just a quench medium that is faster than plain water.  In fact 
it is a medium that was "designed" to equal a NaOH - NaCl solution quench 
medium without the risk of the caustic.

Dave Smucker

----- Original Message ----- 
From: "Bruce Freeman" <FREEMAB at pt.fdah.com>
To: <theforge at mailman.qth.net>
Sent: Wednesday, December 29, 2004 9:22 AM
Subject: Re: [TheForge] quench questions


> Talk to Chuck Robinson about this.  (He's on this list.)  He hardens
> knifemakers anvils (200lb+?) in superquench.  I've got his video.
>
> Bruce
> NJ
>
>>>> osan at netlabs.net 12/28/2004 9:57:16 PM >>>
>
>
> Peter Fels And Phoebe Palmer wrote:
>> My fuzzy memory is that Rob G said he had used it for  A36 hammer
> dies
>> and it yielded " Enormous toughness".......PF
>
> What size dies, though?  I cannot imagine that it would suck the
> heat
> out of a 200# chunk of steel quickly enough, but I may be wrong.  I've
>
> never tried it on anything larger than about two pounds.  Qorked great
>
> for that, though.  :)
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