Salt Quench

[Golden_eagle]

I want to try quenching in a 10% salt solution. I've found a website where someone likes to use a 10% salt solution and i'd like to give it a try.

But what exactly does a 10% solution mean? 10% by weight or 10% by volume?

10% by mass OR IN OTHER WORDS: use a one gallon bucket, ten gallons water to one- one gallon bucket full of salt

[blksmth]

Golden eagle, I do not think it makes much difference if you are over or under with the salt. I have read that you should be able to float a potato if the salt is at the right proportion. I have not tried it myself. I'm sure you know that the salt is more severe than still water alone and works by helping to eliminate the air bubbles that tend to surround the hot iron being quenched.

Dick Nietfeld, Shady Grove Blacksmith Shop, Shady Grove Blacksmith Shop

[mark stephen]

Many steels cant be salt quenched.You would have to have the ITT chart for the steel your quenching to determine if you can use low temp salt as a quench medium.Most scrap steels need a faster quench (5160,1095,)Use a vegatable oil.

[Mills]

veg oil is faster than brine? I had thought it was the other way. I seek enlightenment.

[markb]

[ThomasPowers]

Hmm, I'm going to have to look into getting some cottonseed oil....

[mark stephen]

Yes veg.oil is faster.If you look at, say1095s itt chart ,the nose of the curve will tell you if you need water ,oil,or if you can use salts.1095 needs to be quenched fast to harden.I use salts for 0-1 and l-6 only.I use commercial quench oils for everything else.Hope this helps.

[blksmth]

Salt is a faster (hardens quicker) quench than water. Water is a faster quench than oil. That is a good chart posted by Marcb.

Typically a salt quench is only used on larger pieces of steel, primarily plain carbon water hardening steels. It could break small pieces as it would be too quick.

1095 is a water quench steel with a shallow hardening depth. If thin pieces (under 1/4") of 1095 are quenched they might break in water therefore oil might be a more prudent and slower quench for the thin pieces.

If you were making a hammer head out of 1095, you would want to quench in water to get as deep a hardness as possible and temper the eye and faces to an appropriate hardness (RC50 to RC55).

Note that in Marb's chart, moving fluid is a quicker quench that still water.

[mark stephen]

Salt is faster than water?Sorry, but its the other way around.Im taking about heat treatment salts.These are low temp salts used by the steel industry for quenching and tempering certain steels.Quench a piece(i dont care how thin)of 1095 in these salts and you wont harden it because its a slower quench medium than oils(true heat treat oils or veg.oil).Water hardening 1095 is to risky and will most likley cause cracking.Id choose a deep hardening steel for a hammer head.