Can Someone Explain Annealing Brass

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By Visible Red I mean it just becomes visible. I may be heating it too much but the process has worked for me.
 
And then there are Reloader’s such as myself that do not anneal at all rather use dies that closely match my chambers and only move my brass .0015-.002 when resizing, I do not experience work Harding other shooters have even after 20 loading sessions.
So two sides of a coin...
 
I get 8 to 12 reloads with perfectly acceptable results before I start losing them

For 223/5.56 brass, what's a safe number of times to reload the brass before prudence dictates we discard it? I'm not going to bother annealing, as I have more 223 brass than I'll ever use.
 
Is cartridge brass still used that is a 70/30 mix of copper and zinc? If so I found a paper with most of the answers I was after. Faster heating requires higher temperatures, but recrystalization was complete by 610 to 720 degrees Fahrenheit. The only question I haven't answered is how much cold working is actually being done? There is a minimum amount or recrystalization won't work, but that's typically very low.
 
Annealing starts at 800 degrees F. Stress relieving is 400 degrees F.

Annealing is temperature VS time.
Depleating zinc from the brass ruins it. Vaporization temperature of zinc (about 1600 ° F) is that the metal turns to a gas, such that it can be easy to inhale. Not good.
Look for Blue-green to pale green flame as zinc vaporizes.

Is cartridge brass still used that is a 70/30 mix of copper and zinc?
Yes. Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI
when work hardened.
 
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If I recall there is about 10 different brass alloys being used. You will notice this when you start annealing as in flame color change over time. Also the temperature gradient of the brass will be slightly different. Some mfg require just a second more.
 
Candle method https://www.thehighroad.org/index.p...d-of-annealing-question.862531/#post-11369028

candle flame to anneal brass.


Made a sponge donut about 3/8" thick & 1 3/4" round. Wet sponge with water. Keep case neck/shoulder low in the flame.

Heat case while rotating 180 . When you hear water boiling, anneal is done.

243 win brass, about 30 seconds or till water sizzles. Any less time and brass in just stress relieved. Temperature + Time = Annealed.

I have played with the candle annealing . The test batch didnt come apart.
20200124_194833.jpg

The carbon will need cleaned of the brass after it cools. Use fine steel wool.
 
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Years ago, I worked at a company which employed a full time metalurgist. The first time I visited his office, I had to take a minute to laugh at his bookcase: books on metalurgy interspersed with books on witchcraft, magic, and sorcery. It was his fitting little joke about his craft.

I don't pretend to be an expert on metalurgy, not at all. But here is some of what I have gathered on the topic.

The physical properties of materials include hardness (resistance to deformation), tensile strenght (how hard do you have to pull on it to break it) and ductility (the ability to be formed). What reloaders are mainly interested in is ductility, since we are forming the brass to a new shape. As nearly as I can tell, there is no easy measure of ductility, but as hardness goes up, ductility goes down. So, often we look at Rockwell hardness, and figure that it is a reverse indicator of ductility. It's not really a direct measure, but it is better than a poke in the eye.

Like most metals, cartridge brass has a grain structure. There is a fun process for etching brass to look at grain structure, but it is not likely to happen in my workshop. The larger the grains are, the softer the brass is. Annealing reforms the grains. Grain size is a good measure of state of annealing.

Grain growth in cartridge brass starts just a bit below 500F. You can anneal brass at that temperature, but you will have a long wait. And unless you do something very clever, you will probably also anneal the case head, which is bad juju.

Holding the brass at temperature twice as long gives you about twice as much annealing. But when you increase the temperature, annealing time drops exponentially. There is no single, unique combination of time and temperature that is better than others. You adjust your heat and set your time accordingly.

I found the temperature pencils approximately unuseable. A few years ago, they changed the formula and now they are a PIA to use. So how should a reloader estimate temperature? The old metalurgists would heat the brass until the bluish oxide layer formed. And that works acceptably well. I did that on my wife's gas range, and was well satisfied with the results. Another good solution is the molten salt bath. The thing that won't work is the inexpensive optical thermometers (pyrometer). Those take in about a 1" field of view, which is too large for cartridge brass.

With molten salt, it is trivial to control the temperature of the bath to within a few degrees. As I said in my video, it cost me $14 for a controller and $5 for a high temperature K thermocouple. Dunk the mouth of your brass in the heat bath, and you quickly have very uniform heat in the brass.

Some sources indicate that at 820F, satisfactory annealing for cartridge brass happens in about 3 seconds. So I tried it. I scavenged a couple of rectangles of brass out of a rifle cartridge. One of them, I gripped with 2 pair of pliers and bent 90 degrees, then back to flat. It only took 8 such cycles to cause the brass to crack at the bend. The other piece was annealed for 3 seconds in the salt bath, then bent back and forth. Every 6 cycles, I put it back in the bath for 3 seconds. After over 100 cycles without failure, I gave up. The ductility of the brass was obviously far better than the untreated sample. And ductility is what we're after.
 
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Ductility is measured as % elongation. The lab I worked at did tensile testing. Standard sample length was 8". 25% elongation was required to pass, so the samples had to be at least 10" long before breaking.
 
Watch Eric Cortina's YouTube videos about annealing. He performed some tests which yielded very surprising results and dispelled some common thoughts about annealing.
 
Ductility is measured as % elongation. The lab I worked at did tensile testing. Standard sample length was 8". 25% elongation was required to pass, so the samples had to be at least 10" long before breaking.
Yup.

Destructive test, though. So not easy for reloaders. A triangular diamond point with known force will give you Rockwell, which is easier to do, but as you point out, not exactly measuring the quantity of interest.
 
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Cartridge brass- Olin-

Modulus of Elasticity is 16,000,000 PSI. This means to pull a 1.000 inch long strip to 1.001 inch long induces a 16,000 PSI stress.
So if you pull a 1.000 inch strip to 1.005 inch long, you get about 76,000 PSI, which is the max obtainable.
 
I like this!
the Socket and Drop It method


Oh how incredibly complex is the function of the humble and lowly brass case.
The front of the case needs to be soft so it can easily expand, releasing the bullet, but, more importantly, expanding/grabbing/sealing the chamber so the hot high pressure gases cannot escape to the rear. The back of the case has to be hard enough and sound enough not to rupture under pressure, letting hot high pressure gases escape rearward.
 
Red hot is much too hot. My inexpensive, simple method:
As I use the tip of a propane flame to heat all around the circumference of the neck of the case (several methods for rotating the case, including the socket and drop way) you will see a blue ring form and expand down the neck of the case to the shoulder. That blue ring is is in the 400 Deg F range. close enough for the rifles I shoot, anyway. When that blue ring meets the lower edge of the shoulder drop it in your cooling water. The case is adequately annealed. Perfectly annealed?.. no, but I have a set of 30-06 cases at 15X fired using this method at minimal expense.
 
The brass work hardens, as that is the only way to harden cuprous alloys. This hardening is the increase of dislocations in the crystalline structure. Metal atoms have metallic bonds, which means they arrange in a lattice. An irregularity or defect in the lattice is a dislocation, which introduces strain into the structure. This strain is hardness, because it makes the metal less ductile. Once the amount of dislocations in a region gets too high, the metal will suffer brittle failure (like bending a paperclip back and forth until it breaks) Annealing adds energy into the lattice and allows the atoms to move and rearrange back into a lower strain state, which means the metal is softer/more ductile.
 
I use socket and drop method with a battery drill on low speed. 5 seconds flame time with a propane torch works with my range fired brass in 223. I anneal all cases commercial or military. I reformed two hundred 270 Win to 25-06. What worked best was anneal neck and full shoulder to dull red in ambient garage light. I full length resized to 25-06, trimmed to correct length, and deburred case mouths. I loaded 5 rounds with a proven accurate load and headed to the range. Using 75 gr HP Hornady bullets at 100 yards there was one hole under 1/2" in diameter. That will work for prairie dogs next summer.

I may overheat the necks of all my brass, but resizing is much easier, there are no more cracked/split necks after firing, and group sized have not changed. The 5 second flame time means that I can anneal 100 cases in about 10 minutes. As emphasized in several posts, consistency is important. I use a cake pan sitting on scrap wood blocks to hold the hot cases after annealing. My process appears to produce good results, is quick and simple, and I am satisfied with group sizes.
 
There's a lot of information here, and some of it could lead you astray. Some is good advice. Do some research and find some detailed information from a reliable source, otherwise you could end up ruining brass at best, or ending up with a separated case stuck in your rifle with potential catastrophic results. Study up!
 
There's a lot of information here, and some of it could lead you astray. Some is good advice. Do some research and find some detailed information from a reliable source, otherwise you could end up ruining brass at best, or ending up with a separated case stuck in your rifle with potential catastrophic results. Study up!
Well...
Which is which?:confused:

Those are steep circumstances, with no preface...:scrutiny:
Take a stand. What do you, actually, say?...


That any of this is not detailed and from a reputable source is completely laughable.
 
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