Case annealing question

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  • Last Post 19 August 2019
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max503 posted this 10 August 2019

(Not sure what category to put this in, and I've never annealed a case and don't plan to.)

If I want to anneal a piece of steel I would heat it up then let it cool slowly.  If I want to harden it I would quench it in oil or water.

If I want a harder bullet I drop it from the mold into water.

If I want softer gas checks I heat them then let them cool slowly inside of a pipe nipple with caps on each end.

Question: So why, when people anneal case mouths, they heat the neck and shoulder then quench the case in a liquid?  Seems quenching would harden the case rather than soften it and make it more malleable.

This question has kept me up many a night wondering.  (Just kiddingtongue-out)

I'm kidding about this keeping me awake at night, but I have wondered what's so special about brass cases that they soften when you quench them and every other metal hardens when you quench it.

Thanks in advance.

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RicinYakima posted this 10 August 2019

"Question: So why, when people anneal case mouths, they heat the neck and shoulder then quench the case in a liquid?  Seems quenching would harden the case rather than soften it and make it more malleable."

Copper based metals do not harden by water quenched, only iron based metals. What people are trying to do is keep the heat from the head of the case. If the head of the case is soft, it will not hold pressure and blow out. The reason the head stamping and primer hole operations are done last, is to work harden the case head.

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Larry Gibson posted this 10 August 2019

RicinYakima nailed it; "What people are trying to do is keep the heat from the head of the case." 

Additionally, with the method I use, is the water cools the case quickly so I can remove the case from the Lee shell holder.  I use that in an electric screw driver to turn the neck/shoulder area of the case evenly in the propane flame.  If not water quenched to cool the case production would be extremely slow waiting for the case to air cool.

LMG

Concealment is not cover.........

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mrbill2 posted this 10 August 2019

Every thing you will ever want to know about annealing brass you can find on You Tub

Do a search : Annealing Brass Cases

mrbill2

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Ken Campbell Iowa posted this 10 August 2019

..an interesting thing about annealing brass ... you are really " stress-relieving " it ... and the correct temperature is just under a dull red .... but for practical purposes, dull red is an easy way to get it close.

.. and for today's non-interesting trivia, the brass glows red not from heating up, but from cooling off.  

ken

 

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Bill2728 posted this 10 August 2019

With an electric screwdriver, a 1/4" socket adaptor and an appropriate size socket makes dumping the case easy.  The socket wall helps keep flame away from case head as well.  I keep adaptor, sockets and driver charger in a cleaned out peanut butter jar, everything all together.

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max503 posted this 10 August 2019

"Question: So why, when people anneal case mouths, they heat the neck and shoulder then quench the case in a liquid?  Seems quenching would harden the case rather than soften it and make it more malleable."

Copper based metals do not harden by water quenched, only iron based metals. 

 

 

But I'm still wondering why lead is not iron based but it hardens when quenched.  Probably other ferrous metals do too.  

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RicinYakima posted this 10 August 2019

Lead alloy we use in bullets is not actual a "metal" or a "compound" but a mixture of different metals. It hardens in different mechanism than iron (all ferrous metals are iron based). A metallurgist told me that hardening of bullets is aligning the crystals of antimony and tin to larger structures. The lead takes no part in the process, just is the solution the others are in. With iron the carbon and other metals are chemically bonded to the iron and its crystals are based around the iron.

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John Carlson posted this 11 August 2019

I heat cases in a deep well socket (1/2" for 30-06) and let them air cool.  Heat transfer to the head is negligible (you can't quite hold them in your fingers, but no where near enough heat to do damage).  Some in the more OCD branch of the point blank benchrest community anneal after every firing.  I do it once a year (long winters up here) or about every 8-10 firings.  

John Carlson. CBA Director of Military Competition.

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John Alexander posted this 11 August 2019

John,

What is a deep well socket?

John

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max503 posted this 11 August 2019

I seems with copper it doesn't matter if you quench it or let it cool slowly.  It still softens, apparently.  I was just wondering because other metals harden if you quench them and soften if you let them cool slowly.  Even lead.

 

 

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Bill2728 posted this 11 August 2019

Image result for standard vs deep well socket

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John Carlson posted this 12 August 2019

Yep, that's it.  

John Carlson. CBA Director of Military Competition.

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max503 posted this 18 August 2019

I received a email asking me if this issue has been solved.  Not trying to be difficult, but I still don't understand why ALL other metals harden when quenched, but apparently, bullet cases do not - they soften.  

Am I missing something here?

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beagle6 posted this 18 August 2019

Just for the record, steel won't harden unless it has at least .3% carbon.

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Carl Pegg posted this 18 August 2019

Beagle is correct. Carbon is the main alloying element that makes steel harden when quenched. Very low carbon steel must be carburized or it will not harden by a simple heat and quench cycle. Also, the temperature at which steel is heated prior to quenching is critical. If it is not heated enough, it won't harden. The only way to harden brass is to work it, i.e., bend it, smash it, squeeze it and our reloading processes do a good job of it. Just like Ken said, heating the brass stress relieves it and will do so whether quenched in water or not. Most people quench it to avoid heating the case head which must remain hard. Lead alloys, I believe, will only get harder when water quenched if sufficient quantities of antimony and arsenic are present, but somebody correct me on this if I'm wrong. I'm a pretty lazy caster who shoots mild loads of whatever mystery lead I have on hand.

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JimmyDee posted this 18 August 2019

I still don't understand why ALL other metals harden when quenched, but apparently, bullet cases do not - they soften.  

Am I missing something here?

It's not quite that simple.

Copper, silver, gold, and their alloys can be work-hardened.  It is work-hardening that we want to reverse when annealing cartridge cases.

In general, these metals are annealed by heating, holding, then quenching.  The temperature and the time for which each is held at temperature depends on the metal.

Cartridges are a special case: we want to anneal the necks but not the web or the head; that's why we immediately quench.

Heat is used to harden, temper, and anneal a wide variety of alloys.  The process (heating, specific temperatures, rates of change, soaking, cooling, quenching, &c) and effect depends on the metal.  They're not all the same.

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RicinYakima posted this 18 August 2019

Max503, " I still don't understand why ALL other metals harden when quenched, but apparently, bullet cases do not - they soften." Your statement is in error twice. All metals don't harden when quenched. Quenching cartridge cases have nothing to do with their softening. HTH Ric  

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TRKakaCatWhisperer posted this 19 August 2019

Work hardening increases the grain size.  It makes the metal(s) brittle.

Annealing - heating to a specific temperature reduces the grain size (in the crystalline structure of the metal(s).  Simply cooling is all that is needed as the grain structure has changed.

Iron/steel is a different animal - heating to a specific temperature produces a specific grain structure (there are several).  Quenching preserves that specific structure (and hence it's characteristics).

 

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Brodie posted this 19 August 2019

When they talk about Work Hardening non-ferous metals it brings to mind when I used to hand forge Sterling Ware and specialty items.  Sterling Silver, nickle, jewelers bronze, brass and copper all get harder every time you strike it or even try to change its shape (eg. resizing in a die, and firing the case where it expands back out to meet the chamber walls).  When you are pounding a blank of one of these metals into a specific shape you can feel the metal hardening, and the sound of the hammer changes; becoming sharper and higher in pitch until the metal cracks after repeated blows or you stop and anneal the piece.  You have to stop before that :"One more blow," or it will crack and split on you.

I think that you can also "feel" how the cases are hardening when you resize them.  They will get just a little bit more brittle with each resizing until the neck cracks and splits.

B.E.Brickey

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