[TheForge] Harden & temper

[Jerry Frost]

Salts and caustics also raise the boiling temp of water.

As I read the part of the article I could, I gathered the benefit of this 
type of heat treat process is it yields a tough yet malleable result.

Of course I could've missed something, I skimmed the article and got 
distracted by graphenes. <sigh>

Jer
----- Original Message ----- 
From: "David E. Smucker" <davesmucker at hotmail.com>
To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Thursday, June 16, 2011 6:29 PM
Subject: Re: [TheForge] Harden & temper


> All quenching with a water based quenchent above 212 F is based on the
> physics of flashing water to steam.  For this to be really fast we must
> prevent a stable steam film insulating the surface.  This is what brine
> does, this is what a caustic solution does, this is what "super" quench 
> does
> (there is nothing "super" about super quench), this is what high velocity
> sprays do.  All of the above are very close to twice as fast as still 
> water
> with limited movement of the part.
>
> In sheet applications, (continuous web moving in a process line), plain
> water sprays are hard to beat on an effective cost bases.  If we are 
> making
> auto sheet -- there is no other bases than cost.
>
> Dave Smucker
>