Annealing/Normalizing

[WannabeSmith]

I'm sure this is a dumb question but is there anything wrong with leaving the piece you are working on in the embers in your forge as a form of normalizing/annealing not quite sure what it would be called. I'm assuming there is something wrong with it sicne i have never read about it. Anywho I was thinking about doing that with my piece tonight. So finding out

[Sabre]

i am pretty shure if u leave it in the hot embers an leave it till its cool it will sofen it up...if i am wrong please correct me!

[Falconer]

Annealing and normalizing are two different things. If you attempt to anneal your work in a cooling forge...it will likely cool too quickly. Annealing is best done in vermiculite overnight. That allows the piece to cool very slowly. and takes the stress / memory out of the steel.

Normalizing is done by leaving it in open air until cooling. It's sometimes only a subtle difference but on a molecular level the latter can still leave some stress in the steel...depending, of course, on the kind of steel used.

Buy some vermiculite at a Home Depot; put it in a five-gallon bucket and bury your work in it immediately after taking it out of the forge. Leave it overnight and you're done.

[Quenchcrack]

If you want to slow the cooling process down, heat up a thick chunk of steel and bury it in the vermiculite. Then put your work piece near the chunk and let the chunk keep your work piece warm and cooling slowy. By the way, metals don't have molecules, they have crystals. I know picky picky.

[Sask Mark]

Actually, all matter is comprised of atoms. Combinations of atoms bonded together are molecules. Crystals are composed of atoms or molecules bonded in specific arrangements.

All the elements that make up the metal you are working are made of the atoms that you find on the periodic table.

[Quenchcrack]

Sask Mark, atoms are connected in metals by metallic bonds. Molecules are connected by covalent bonds. Yes, all matter is made of atoms but the way the atoms are bonded is different between metals, organics, and ceramics.

[WannabeSmith]

Haha thanks for all the responses guys! I know the two are different I just was leaving a fire unattended to type this (took like 30 sec) and my mom was on my butt about it so I typed anneal/normalizing to symbolize I felt like this was kind of a mix between the two because it wasn't air temp but it wasn't a closed space without air movement. I am just doing a spike and wasn't particular on either form, although I thought about annealing my ashes were not prepared.

Thanks a ton again guys. =D

[Falconer]

"atoms are connected in metals by metallic bonds. Molecules are connected by covalent bonds. Yes, all matter is made of atoms but the way the atoms are bonded is different between metals, organics, and ceramics."

Excellent point...if you were working with pure iron that would be the case. Steel, however, is made up of iron crystals interspersed with carbon atoms and other atoms and molecules that align the iron crystals in different ways to make it stronger etc.

Edited November 19, 2008 by Falconer

[Matt in NY]

I've been reading a bunch of stuff and one place (don't know which place) did mention leaving the piece in the cooling fire as a way of annealing.

[DC712001]

"Ashes" are considered a type of insulating-media to slow-cool metals, as is sand, vermiculite, lime, or other insulating materials, etc in the packing-process, as opposed to furnace-cooling, water, brine or oil-quench, "rapid" or "still" air-cooling, etc.

This link has a brief (1-page) description of various thermal or heat-treatment processes:

Fundamentals of Airframe Repair

Or this slightly longer (12-page) link:

http://www.globalsecurity.org/military/library/policy/navy/nrtc/14250_ch2.pdf

Edited November 19, 2008 by DerekC

[petere76]

Wannabe,

Just a 5 gal pail of wood stove ashes will do the trick. I have used this method for a few years without any difficulty.

Peter

[Frank Turley]

The only dumb question is the one not asked.

What we've left out here is the temperature you reach before annealing or normalizing. For plain carbon steels and some low alloy steels, you want to reach 100 - 150F above critical before cooling. The ember fire would be a reasonable anneal resulting in slow cooling assuming you reach the annealing temperature first, usually in the cherry red ranges. On some high alloy steels, it may be above cherry red. Get the specs from the steel supplier.

Normalizing is done in still air FROM THE PROPER TEMPERATURE.Air cool the piece on a non reactive surface like a fire brick or pile of coke; don't place it on a heat sink, metal for instance. Normalizing takes less time than annealing and is not quite as thorough in terms of softness. Nevertheless, it is a good treatment for carbon and some low alloy steels, as it enhances austenite formation before hardening. It lessens large carbide formation, which can occur with annealing. The large carbides are undesirable.

http://www.turleyforge.com Granddaddy of Blacksmith Schools

[thingmaker3]

Another detail worth noting is we're talking about plain-carbon and low-alloy steels in this thread. Just stuffing a hot piece of S7 or A2 in ashes overnight will not anneal it. Just stuffing a hot piece of 1045 in ashes overnight will.

It has to do with how fast the carbon can move through those crystals to collect into carbides. Any good metallurgy text available through your library system will help with understanding.

[Larry H]

I use a coke forge, for thirty years, so it stays hot for hours and could still burn you in the morning. When I put a piece in for annealing, I heat it orange and leave it next to but not in the fire. in the morning you can have your way with it. It is science but not rocket science