Complete annealing?

[tomcat818]

Complete Annealing is carried out by heating above the upper critical temperature, and then cooling slowly in a very controlled manner. It requires complete knowledge of the isothermal transformation diagram and the cooling transformation diagram of the alloy so that the desired microstructure of the alloy is achieved.

This came to mind after watching many videos on annealing brass and realizing there was little to no discussion about cooling time other than ambient cooling or dropping brass in water. Some compared non-virgin annealed brass with no regard to cooling to non-annealed non-virgin brass while monitoring seating pressures and discovered the annealed brass had more pressure standard deviation than non.

Heating the alloy is just the first step and does not constitute annealed brass since there is no controlled\timed cooling process. In the glass industry these temp over time controlled ovens are called annealing ovens and the glass (heated to ~2,400F) takes ~ 14hrs to be brought down to room temp in these ovens so it is not overly brittle.

I understand this topic may be more suited to the bench rest crowd but with the prices being charged for quality brass these days I would love to get more firings while maintaining accuracy.

I'm asking these questions because I've reached the customary 2-3 firings were some believe annealing should take place on ~150 pieces of brass (100 Petersen which came annealed, 50 Nosler Premium which did not). I want to make the most informed decision possible before plunking down a bunch of money to implement this process.

Anyone utilizing a controlled cool down in their brass annealing process?

 

[Rick Richard]

From what I have read and understand, brass is not affected by rapid or slow "cool down".

 

[PopNFresh]

maybe email somebody like AMP, I bet they have a satisfactory explanation on why soak time while heating and cooling time aren't as necessary as with steel

 

[Hugger-4641]

Snipped from another forum. Having worked for Kaiser Aluminum for several years in an extruded bar facility, I can assure you this is also true of aluminum. The heating and soak at high temp provides the anneallng, cool down is irrelevant.


Like I said-Non ferrous metal is annealed buy the heating. This is proven fact.
I anneal 5.56mm, 7.62x51mm, 30-06, 300WM, .45-70, .45-90 and 50BMG.
Quenching is for ferrous metals ONLY.
http://www.6mmbr.com/annealing.html
http://www.texas-mac.com/Annealing_Case_Necks.html
Facts, are stubborn things,

 

[MagnumManiac]

Annealing brass is heat and time, cool down, quenching or not makes zero difference to brass.
Your above statement resonates the tempering characteristics on aluminium and titanium, rather than ferrous metals.
I used to anneal copper bars for heat sink windings, it was air cooled on the ground.

Cheers.

 

[ButterBean]

 

[Varmint Hunter]

Hobby annealing is a bit like going to church, it's all based on faith. I do anneal my cases, but I haven't a clue as to whether or not it is being done in a way that actually achieves the perceived goal.

To me, it's like putting expensive motor oil in your car. You take it on faith that the extra money you just spent is benefitting you somehow.

I reloaded for decades before anyone even mentioned annealing a brass case. I can't recall ever having a split neck. I normally got good case life (about10x before tossing). Why do I anneal? Because you guys make it seem necessary.

 

[ButterBean]

Hobby annealing is a bit like going to church, it's all based on faith. I do anneal my cases, but I haven't a clue as to whether or not it is being done in a way that actually achieves the perceived goal.

To me, it's like putting expensive motor oil in your car. You take it on faith that the extra money you just spent is benefitting you somehow.

I reloaded for decades before anyone even mentioned annealing a brass case. I can't recall ever having a split neck. I normally got good case life (about10x before tossing). Why do I anneal? Because you guys make it seem necessary.

As long as you do the same thing every time your doing it right, keep on keeping on

 

[tomcat818]

maybe email somebody like AMP, I bet they have a satisfactory explanation on why soak time while heating and cooling time aren't as necessary as with steel

AMP site does have a very interesting study published:

Induction Annealing Brass | Our Research | AMP

View the latest articles from AMP Annealing. Get tips and tricks from our R&D. Here we upload articles to provide your the best possible information on innovations in the annealing process.

www.ampannealing.com

I noticed an increase in my SD's from virgin annealed Peterson brass and 2nd and 3rd firings. From 3-4 to 6-9 and last firing 8-11. This article talks about neck tension variance across several brass prep processes. I would like to see my SD's consistently <6.
They believe and have studied timed cooling cases and it has no measurable affect beyond air cooling

 

[Dmagna]

No need to control cooling brass, it doesn't affect anything.

 

[tomcat818]

Snipped from another forum. Having worked for Kaiser Aluminum for several years in an extruded bar facility, I can assure you this is also true of aluminum. The heating and soak at high temp provides the anneallng, cool down is irrelevant.


Like I said-Non ferrous metal is annealed buy the heating. This is proven fact.
I anneal 5.56mm, 7.62x51mm, 30-06, 300WM, .45-70, .45-90 and 50BMG.
Quenching is for ferrous metals ONLY.
http://www.6mmbr.com/annealing.html
http://www.texas-mac.com/Annealing_Case_Necks.html
Facts, are stubborn things,

Hugger,
I knew someone out there had the empirical evidence to answer this question.
Now I know
Thanks

 

[MarkInPA]

Snipped from another forum. Having worked for Kaiser Aluminum for several years in an extruded bar facility, I can assure you this is also true of aluminum. The heating and soak at high temp provides the anneallng, cool down is irrelevant.


Like I said-Non ferrous metal is annealed buy the heating. This is proven fact.
I anneal 5.56mm, 7.62x51mm, 30-06, 300WM, .45-70, .45-90 and 50BMG.
Quenching is for ferrous metals ONLY.
http://www.6mmbr.com/annealing.html
http://www.texas-mac.com/Annealing_Case_Necks.html
Facts, are stubborn things,

Thanks for sharing the articles. There is some good information there.

I just started to anneal my cases. I haven't even fired any of my ammo that I annealed the cases for. After reading this, it makes me wonder if I just ruined a bunch of ammo by trying to anneal. Let me explain that my method was by using two torches, a socket and a cordless drill. I would hold the case neck in the flame while spinning it with the drill for an approximate count of 3 when either the flame would turn color or I could just see the case begin to change color. One of the take-aways that I have from reading this article is how consistent was my method. I am sure that some of my cases were heated to different degrees and annealed to different amounts. This doesn't seem like a recipe for accuracy to me.

I have also tried using the Templaq. The Templaq works but, it leaves a film on the inside of the case neck which must be removed if it can be removed. I chucked up bore brush in my drill and ran it through the neck. I wasn't real wild about this idea and am not sure if it ever got all the Templaq out.

I noticed that the carbon inside the case neck seems to get burned off to. What effect does this have on accuracy. I always thought that a little bit of carbon provided some lubrication while bullet seating. One reason it is good to clean cases but not to go overboard and make them squeaky clean.

The bottom line for me is that I believe annealing will improve accuracy but, it must be done in a proper and consistent manner.