Tempering quench recipe
NewsGroups | Search | About
Login Password
Register Now! Lost Password?
 alt.crafts.blacksmithing    Post an article   get this group's latest topics as an RSS feed add this group's latest topics to your My MSN content add this group's latest topics to your My Yahoo content
Subject Author Date
Tempering quench recipe theChas. 09-12-2007
Posted by spaco on September 15, 2007, 12:43 pm
Please log in for more thread options
An earlier poster on this topic said something about trying super quench
with high carbon steel and see what happens, but wear safety glasses,
etc. What he meant by that was that the higher carbon steels are very
likely to crack, maybe with disasterous results.
The super quench, from my experience, would be toooo effective,
especially if the parts had any rapid changes in cross section.

On last (for me) comment on the utility of salt in the quench:
I read, some time ago, that the reason for adding salt (a LOT of
salt) to the quench water is that it DOES speed up the cooling rate, but
only over a narrow range of temperature, right in the upper end of the
transformation range, then it is actually slower from there on down.
So, you have to know the shape of the TTT curve for the job at hand and
then test the system to make sure it works anyway.

George Dixon, a well known blacksmith from Swannanoa, NC who taught many
of us tool making, showed us how to harden one of his favorite tool
steels, S1, with salt water, even though it is listed as an oil
quneching steel in "the book". The reason for doing this is to take
advantage of S1's somewhat strange TTT curve. By doing this, we get a
few extra points Rc in the body while actually over hardening the
cutting edge of chisels designed to be used hot and cold. Sometimes,
that chisel edge breaks off in first use, but grinding it back a bit
gets past the VERY brittle edge and to the point where it works, hot or
cold, for a long, long time.
I say all this just to point out that you can start with the theory,
but you need to check things out in practice and adjust as needed to get
a useful end result.


Pete Stanaitis
----------------

Chilla wrote:

<snip>
>
> I suspect that the super quench wouldn't be very effective with high
> carbon steels, where the addition of carbon of benefit.
>
> So are the limits of super quench for water hardening steels and mild
> steel?
>

Posted by Martin H. Eastburn on September 15, 2007, 11:28 pm
Please log in for more thread options
It is speed and rate of speed (acceleration).

Some metals are water - require a fast fixing.
Some metals are oil - require a slower fixing.
Some exotic metals are in exotic quenches and might have half a dozen
dips in and out of the bath or a certain short time... Shell work not
total.

I suspect there are masters that can do multiple zonal using all sorts
of exotic tricks of cooling and re-heating.

Water happens to be one of the very best liquids that absorb heat.
Exotic chemicals HydroFloro types are like water but are like gold.

Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Chilla wrote:
> Didn't think of salt that way.
>
> We used to boil our pasta in water and salt the pasta later. We now
> salt the water, I just thought it was for flavour. You learn something
> new everyday :-)
>
> So we have the salt added to increase the boiling point of the
> water(which in effect would reduce steam), and detergent also reducing
> steam. The water allows rapid cooling.
>
> Why not use a liquid that doesn't produce steam at all, and still allows
> rapid cooling?
>
> I suspect that the super quench wouldn't be very effective with high
> carbon steels, where the addition of carbon of benefit.
>
> So are the limits of super quench for water hardening steels and mild
> steel?
>
> Would replacing the water with motor oil, in the super quench recipe, be
> of benefit, or work for that matter?
>
>
>
> Regards Charles
>
>
>
>
>
>
> Martin H. Eastburn wrote:
>> The salt makes the water able to hold a lot more heat and thus
>> have a higher temperature before boiling off.
>>
>> If you cook pasta, one fills a pot and add some salt. The salt
>> makes the water 230 or so degrees F at boiling and not 210. More salt
>> and the temp rises. See what the temp for molten salt is - that is
>> the max.
>>
>> The soap is a water wetter and makes it conform to smaller places on the
>> object to cool.
>>
>> Martin
>

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Posted by Guy King on September 16, 2007, 3:12 am
Please log in for more thread options

> Water happens to be one of the very best liquids that absorb heat.

Hard to beat unless you go to liquid hydrogen, though the consequences
of quenching in a bath of that are probably best avoided!

--
Skipweasel
We have always been at war with Iran. [George Orwell - almost]

Posted by Guy King on September 15, 2007, 6:11 am
Please log in for more thread options

> If you cook pasta, one fills a pot and add some salt. The salt
> makes the water 230 or so degrees F at boiling and not 210.

for that to be true it has to be a saturated salt solution - that's more
than "some" salt and certainly more than is either palatable or good for
you!

That said, there's no reason why you can't use a saturated brine for
quenching - but you certainly wouldn't want to cook with it.

--
Skipweasel
We have always been at war with Iran. [George Orwell - almost]

Similar ThreadsPosted
Quench oil & tempering power hammer dies January 24, 2007, 7:36 am
Recipe/availability for Repousse Pitch February 7, 2008, 4:00 pm
tempering help August 7, 2008, 5:29 pm
tempering tongs and the like September 12, 2006, 5:43 pm
tempering a miners pick?? January 29, 2007, 10:54 pm
clay tempering a european sword blade November 26, 2005, 9:18 pm
Need some specific hardening / tempering information - any help appreciated! February 1, 2007, 7:12 am
1902 E book on hardening, tempering, and forging of steel November 1, 2007, 12:29 pm
Quench oil what is best? January 22, 2007, 9:04 pm
Quench oil question March 13, 2006, 9:43 am

The site map in XML format XML site map
 Contact Us | Privacy Policy