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Jess
02-01-2008, 10:40 PM
Can someone tell me what the minimum temperature to achieve sought after softness in case neck annealing, also what would a maximum temp be? I've heard all the visual things to look for would like to verify with temp probe.

h-bar
02-02-2008, 09:51 AM
yeah glowing red and tip them into the water. I make them glow to just before they melt!!!!

mikecr
02-02-2008, 12:25 PM
Annealed brass is actually ruined. It's stress relieving that's desirable.
It's my understanding that the grain structure of brass is unaffected below 450deg, and that >800deg will cause annealing. So I use 650deg as measured by a probe, in a lead dip.
Using this method, I can take my time and get a deep, well controlled stress relieving.

My brass does not glow at this temp, and cools to a discoloration slightly lighter than new Lapuas.

Jess
02-02-2008, 08:34 PM
Thanks alot Mike ! That was what I was looking for.

h-bar
02-03-2008, 08:01 AM
Jess- Annealing is very subjective in what works for one guy may not be what the other guy is looking for. Mikes answer is incorrect in that it is annealing the material just not as completely as can be done. I personally like the cases very soft that way they seal the chamber in a very rapid manner. The only time annealed cases are ruined is if you anneal the head section of the case. Annealing brass disorganizes the molecules of the brass. The more you heat the brass toward its melting point and the quicker you cool it will determine how disorganized the molecules are thus how much annealing has occurred.

Mikecr-Hey can you state something factual next time and have it not being based entirely on opinion!!!!!!!!!!1

Charles E
02-03-2008, 08:52 AM
Jess,

here is one good link.

http://www.varmintal.com/arelo.htm#Anneal

Read carefully. The "dull red" is given as about 750F degrees. I've always used 700F, as the closest I can measure to 670F, which is about right for most cartridge case alloys.

There is another reasonably good review at 6mmBR.com

If you follow H-bar's recommendation -- bright red in a normally lit room, you will have very even neck tension -- because the brass will have likely lost all springback. It depends on what temperature he feels is "bright red." Most of us like to be able to control neck tension. It will be very weak in terms of yield strength, which is probably OK safety wise, since the case neck is supported by the chamber at the neck.

I'd say this is a topic for a book, not an internet message forum, and even here, you need a book by a metalurgist familiar with what you are trying to achieve.

vinny
02-03-2008, 10:42 AM
Jess
Try this site, it's pretty informative.

www.lasc.us/CartridgeCaseAnnealing.htm

Charles E
02-03-2008, 11:08 AM
Can someone tell me what the minimum temperature to achieve sought after softness in case neck annealing,

As long as we are getting into it, I have no idea what "sought after softness in case neck annealing" means.

Most benchrest chambers fit the case quite well, as do custom dies made for that chamber. There are any number of benchrest shooters who do not want their necks getting softer. Proper neck tension can be maintained by changing the bushing in the sizing die as the brass hardens. I suppose you could do the same with an expander ball if you changed balls as the case hardens, it's just that most custom dies don't size this way, and it can get a bit tough when you have two dimensions varying with springback (how much you size the neck down, how much you expand it back).

So there is an assumption buried in the original post, and yet another variable, namely, how much bigger than the virgin case, and the sizing die, is the original chamber? Whether to anneal at all can depend on the answer to these.

mikecr
02-03-2008, 11:46 AM
H-bar, it's not my intention to P anyone off

I can't point you graphs or definitions, but I assure you they are out there. My numbers are repeated everywhere you'll look. In KL's brochure linked above:

"Brass which has been "work hardened" (sometimes referred to as "cold worked") is unaffected by temperatures up to 482 degrees (F) regardless of the time it is left at this temperature"

"The critical time and temperature at which the grain structure reforms into something suitable for case necks is 662 degrees (F) for some 15 minutes. A higher temperature, say from 750 to 800 degrees, will do the same job in a few seconds. If brass is allowed to reach temperatures higher than this (regardless of the time), it will be made irretrievably and irrevocably too soft. Brass will begin to glow a faint orange at about 950 degrees (F). Even if the heating is stopped at a couple of hundred degrees below this temperature, the damage has been done -- it will be too soft. "

What's missing here, and that I can't find a source right now to define, is the distinct point between 'annealing' and 'stress relieving'. From memory, >800deg stuck with me as annealing, and ruination of our brass. Below 800 as not annealing.
This is an important distinction and difference because researching 'annealing' will lead anyone to much higher temps than desirable for our purpose.

We are 'stress relieving'

4Mesh
02-03-2008, 12:15 PM
Mikecr,

I'm not sure what you mean by ruin the brass. What is ruined?

If a person was to anneal a case head, yes, that is ruined. Not because it could not be fixed, but because we do not have the presses to fix it and putting it in a gun is asking for some bad stuff to happen. But to do a neck and shoulder, nope. Varmint Al's page that's linked above shows a hypothetical case head after being annealed. That's not exactly what folks do. At least, that's not what I do.

Even if you anneal a sholder/neck dead soft, running it in a die will cause it to work harden again and will have plenty of neck tension. You'd have to get a case mighty hot to destroy it. I'm not sure a propane/mapp torch could do it, except for softening the case head itself.

There are lots of people who "anneal" and don't bother with "stress relieving". Cartridge brass goes through several annealing stages when it's being formed, yet, we take it out of the bag and fire it. Somehow it got harder. So hard in fact, that it get's annealed again before it's sent to us. On Lapua brass, that fact is quite obvious when you open the box.

mikecr
02-03-2008, 01:05 PM
Ken Light defined undesirable results pretty well with his vise-grip test.

4Mesh
02-03-2008, 01:27 PM
Could you point me to the "vise grip" test, post a link?

Is he talking about shorter cases like a PPC/BR?

Is the heat left to bleed down the case and change the head hardness? If so, yes that is bad. I put the heat in fast, then get it out fast. I pick up 300 wsm cases with red hot shoulders with my bare fingers and quench them, so the body is not very hot. After 60 or 80 cases, I have sometimes had my fingertips get a bit smooth, but not burnt. I'm grabbing the case roughly at the .875" point from the base. The case is 2.1" long, and I put the flame on the shoulder. I anneal in Mapp Gas for 4.75 seconds and the case is being quenched within 1.5 seconds of the time the case leaves the flame.

Anyhow, my entire case head is cool enough that it can be held above that area with bare fingers. Not for very long though because the heat is traveling down that case and within I'd say 3 to 4 seconds, I'd better be getting it cooled or I will be burnt.

/edit/
Found it... It's on the page Vinny posted above.

/edit again/
Mike,

All I saw was that he shows you how various degrees of tempering change the case. He does say don't get near the base with the heat in the paragraph before the pliers trick. He also says that overdoing the necks may show no improvement in accuracy, and could even result in worse accuracy. To that, some folks like myself disagree, or at least I disagree if his definition of overdoing is just past the dull red stage. I don't advocate melting the cases! I anneal mine farther than he says in his article though. From what I know about looking at thermocouples, I'd say mine are in the range of 1000-1200 depending on the mood I'm in that day. On that I'm guessing.

Redrock
02-03-2008, 01:47 PM
Others can help with the technical stuff, but when brass gets to hot (when you see color) you are "burning out" important ingredients at which point the brass will be junk and no matter how many times you run it through your die it will be "dead" soft.

h-bar
02-03-2008, 02:49 PM
mike- i am usually pretty passive but I do believe in calling it like it is. Annealed is annealed there is no getting around that. What you do to your cases is annealing just to a lesser degree. I think you will agree to that statement. The rest is all a matter of preference. I like buttery soft case necks!!! Hell I even got lucky and finished third in the world open at williamsport with my buttery soft cases. See even a blind monkey can get a peanut. I think the main thing is to make sure all the cases are annealed to the same specs no matter what method you use.

mikecr
02-03-2008, 09:41 PM
Bill I agree that whatever temp is consistant and works for you is good.

I've Googled around a bit for a single source I've read in the past, without alot of luck. But there is still good info out there that supports my statements earlier.

This spec shows 70/30 brass annealing temperature at 800-1400deg:
http://www.suppliersonline.com/propertypages/C26000.asp
And here: http://www.ansoniacb.com/CDA%20Files/C26000.htm
Well, all sources agree here.

This link defines Stress Relieving as different from annealing:
http://www.matsci.ucdavis.edu/MatSciLT/ENG-45L/Files/Experiment-4.pdf
This one defines stress relieving temp as 500deg and annealing at 800-1400:
http://www.lfa-wire.com/c26000.htm

I think this is the best with better terms
http://web.nchu.edu.tw/~jillc/me/Ch10-%20Kinetics%20-%20Heat%20Treatment.pdf
Pg34 here shows hardness dropping with temps on a graph
It stops at annealing temps
Pg37 graphs recrystallization. It defines grain growth beginning at 932degF
This grain growth coincides with annealing, and recrystallization coincides with most 'annealing' procedures I can find.

Thing is, nobody uses 800 to 1400deg Tempilstiks.
I see 650deg suggestions for tempilstiks, and that is no where near annealing.

Anyway, I may be wrong, but I didn't just make things up and state them as fact. I'm not trying to confuse things, but clarify them.
Does anyone out there think we should apply 800-1400deg temps to our brass?

Al Nyhus
02-03-2008, 11:04 PM
You might find this worth a look.

Cartridge Brass, UNS C26000 (260 Brass), H08 Temper
Categories: Metal; Nonferrous Metal; Copper Alloy; Brass

70/30 brass, CDA 260, CZ106, ISO CuZn30, CEN CW505L

Physical Properties Metric English Comments
Density 8.53 g/cc 0.308 lb/in at 20C (68F)

Mechanical Properties Metric English Comments
Hardness, Rockwell B 91.0 91.0
Hardness, HR30T 77.0 77.0
Tensile Strength, Ultimate 650 MPa 94300 psi
Elongation at Break 3.00 % 3.00 % In 50 mm
Modulus of Elasticity 110 GPa 16000 ksi
Poissons Ratio 0.375 0.375
Fatigue Strength 160 MPa 23200 psi
Machinability 30.0 % 30.0 % UNS C36000 (free-cutting brass) = 100%
Shear Modulus 40.0 GPa 5800 ksi
Shear Strength 330 MPa 47900 psi

Thermal Properties Metric English Comments
CTE, linear 250C 19.9 m/m-C 11.1 in/in-F from 20-300C (68-570F)
Specific Heat Capacity 0.375 J/g-C 0.0896 BTU/lb-F
Thermal Conductivity 120 W/m-K 833 BTU-in/hr-ft-F at 20C (68F)
Melting Point 915 - 955 C 1680 - 1750 F
Solidus 915 C 1680 F
Liquidus 955 C 1750 F

Processing Properties Metric English Comments
Annealing Temperature 425 - 750 C 797 - 1380 F
Hot-Working Temperature 725 - 850 C 1340 - 1560 F

Material Components Properties Metric English Comments
Copper, Cu 68.5 - 71.5 % 68.5 - 71.5 %
Iron, Fe <= 0.0500 % <= 0.0500 %
Lead, Pb <= 0.0700 % <= 0.0700 %
Other <= 0.150 % <= 0.150 %
Zinc, Zn 28.5 - 31.5 % 28.5 - 31.5 %

Descriptive Properties
Hall Coefficient 36 pV m/A T
Velocity of Sound 3660 m/s

4Mesh
02-03-2008, 11:26 PM
Mikecr,

Thanks for the links, there's lots of good info in there.

I'm taking an excerpt from the Experiment pdf

This experiment deals with three very specific types of heat treatments. Each is concerned with producing the desired properties by means of producing the required microstructure. These heat treatments, their objectives and the resulting microstructure are:

Stress Relieving Stress relieving reduces or eliminates residual stress, thereby reducing the likelihood of failure during service, usually by stress-corrosion cracking. It can also be used to improve dimensional stability. Stress relieving temperatures are below the recrystallization temperature. While stress relieving near the recrystallization temperature will require shorter times and will be a more economical process there will be some loss of strength. Using lower temperatures and longer times will preserve strength and will even increase it slightly if the material had been severely cold worked.

Recrystallization Recrystallization is characterized by a rapid change in tensile properties and the formation of a new, strain-free microstructure. Between 35 and 60% cold work is required before recrystallization can occur with increasing amounts of cold working lowering the recrystallization temperature.

Softening, annealing Softening is achieved by heating to well above the recrystallization temperature and holding for whatever time is required to complete the recrystallization process and obtain the desired grain size. Annealing is often used when the material will receive further cold working.

To me, what it is saying about stress relieving is that you end up with brass that is less prone to stress-corrosion cracking. The same loss of strength is going to happen regardless if you anneal or SR. Your SR is done at a higher temp than the one in the datasheet anyhow, which says 500 for an hour. And of course you knew that already.

Recrystallization has no target temp to do is, but is going to change as the brass gets older. I happen to have a lot of very old brass that's been cold worked 30-60 times. Actually, you could say many more times over than that because I do multiple operations on them each firing.

Softening, Annealing if you take a look at the very last sentance says "Annealing is used when the material will receive further cold working."

Now, if you're shooting a PPC, or a very tight neck case, then by all means, the stress relief may be something to look into to make the brass last longer. Don't work that brass in a die. However, if the cases are going to get cold worked (grow in the chamber) and get cold worked in a die, then that is not what you're looking for if you want the longest life from them. For those of us who shoot chambers with more neck clearance, there's no way I can just stress relieve the brass and expect it to survive. It just won't. Also, the necks get so tough, you can't expand them without deforming the rest of the case. Even a few thou of expansion takes a LOT of force.

Last but not least, these temp sticks people use don't really tell you much about the neck. Most people say put the stuff on the shoulder and then anneal (/sr) and the fact is the neck is a TON hotter than that shoulder is. I'd bet that most folk who anneal that way have necks 300f or more higher than they think they do. I do not have any way to check it because a case changes in temp so fast, I don't know what instrument you could use to check it. I have seen thermocouples in heat treat ovens though, and over the years have gotten to where I can pretty much guess a temp pretty close most times. From 900-1800 anyhow. At 800, there is virtually no glow. Even at 900, it's very slight. At 1000f it's begining to get light in the oven. at 1200 things are clearly red, by 1500, they light up a dark room when you pull a large part from the oven and at 1750-1800, they're bright yellow and that parts get'n pretty toasty. You can see through a stainless steel bag there. When putting heat on a neck, I'd say I've seen mine get to 1400 before. Not often though, I don't like to go that high.

One other thing that nobody has said here. A great way to make cases anneal softer without taking the temp quite so high is to quench in icewater. That REALLY softens em up. So if you want a little more cold workability without all the temp and burn marks, use icewater.

mikecr
02-04-2008, 08:57 AM
Great info
Thanks alot

h-bar
02-04-2008, 04:31 PM
4mesh- I mentioned the rate of cooling earlier in the post. I am glad we all came to a consensus on this!!!!!1

dave10xbowles
02-15-2008, 08:14 PM
Get yourself a drill motor. Get yourself a cylinder that you can chuck into
your drill motor where the cylinder will leave about 1/2 of the case exposed.
Then get you a large pan w/Ice and cover with oven foil that packs tight
to the ice. That way the cooling effect of the ice works the best.

How dim the room down low (lights, you know put on Barry White tunes):cool:. Now place the brass in the cylinder after you lit the torch.
Spin the drill motor and insert the neck/shoulder into the white feather of
the flame. Spin for about 5 seconds or until you see the first DARK Rose
color in the brass, NOT!! RED... With gloves remove from the spinning cylinder
and place in the foil covered ice tray. This is what I have done for years.
With consistent results regarding neck tension, and have had SCREAMER
GROUPS with great longevity with my brass. Remember NEVER too HOT
IS THE KEY!!!!!!!!!!!!! With practice this process will fly by, and you will
be able to get good results. Attention to detail to the key!!! No need
for Paralysis by Annalise!!!

Harley Dave Bowles:cool:

4Mesh
02-15-2008, 11:11 PM
Dave,

Are you sayin you're rolling the hot case on the dry side of the foil? Hmm, pretty cool. Does the foil sweat after a while and give you just a little bit of moisture to help move the heat? Or is that not really needed?

I roll mine on a sponge that sits in a saucer with a puddle of water around it and I keep the necks so they are over the edge of the sponge, that way no water spatters in as it sizzles. For the annealing I've built a programmable gizmo that's controlled by a microprocessor for doing mine so I guess yes, I qualify for the parallasis by analysis award!

J. Pendergraft
02-15-2008, 11:29 PM
If you want a fair amount of neck tension then you definitely can ruin cases by overheating. Overheating will make the brass dead soft and you will not be able to obtain much neck tension regardless of what size neck bushing you use during sizing. I have known too many folks that have been there and done that and then wonder why they can't get any neck tension even when using bushings .005-.006" under finished loaded round neck diameter. If you don't want much neck tension then have at it. I don't think you will ever have to anneal again. It's my understanding once you get it too hot and dead soft it will not get hard again no matter how much you work it.

4Mesh
02-16-2008, 12:00 AM
Joel,

I don't understand how so many guys so far in this thread, are of this opinion about the brass never getting hard again after overheating. I've never seen that happen. In fact, I'd almost say that the times where I've gotten the brass the hottest, you know, where the brass was so hot it began to scale. When I did that, yes, it was really soft at first, but I thought it hardened up faster than it did with what I'm going to call a proper annealing temp, which is still higher than some folks here advocate. It hardened so fast in fact that I would have to change my case prep sequence from, anneal, resize, expand, load to resize, anneal, expand, load. If I did the resize / expand after the anneal, I had more neck tension than I wanted.

As I sit here and think of why my situation might be different, it's probably because I run more neck clearance than anybody I know. I work the brass about a mile all the time and perhaps that has something to do with it. Years ago I did some tests on brass and learned a lot about what to expect with various methods of annealing. But I never saw this. Boy, if I can get these necks so soft that they never get hard again, I might be get'n my cut'n torch out this weekend. Especially if I could convince the shoulders to stay that way. :D

h-bar
02-16-2008, 06:54 AM
amen 4 mesh

h-bar
02-16-2008, 06:55 AM
I wish my brass would stay soft at the neck and shoulder forever!!!!!!!!!!

Plugger
02-19-2008, 06:57 PM
In the Honaday annealing kit you have paste that melts at 475 applied .25 down on the body. They think that is about right to get the neck annealed and I hope that they tested it before putting it on the market.