Why Doc doesn't use the term annealed with cartridge cases

[CJ6]

When im putting my bullets in the clips and getting ready to fire I'll be thinking about all this.

I know you know what I'm talking about !

You mean loaded cartridges of course........

 

[paperpuncher]

Or, refer to themselves in the third person.

Yep Paperpuncher hates it when people do this

 

[DonkeyHote]

Being recto cranial inverted , it was worth to upgrade my membership to gold

 

[Area51]

In metallurgy and materials science, annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for an appropriate amount of time and then cooling.

In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to a change in ductility and hardness. As the material cools it recrystallizes. For many alloys, including carbon steel, the crystal grain size and phase composition, which ultimately determine the material properties, are dependent on the heating rate and cooling rate. Hot working or cold working after the annealing process alters the metal structure, so further heat treatments may be used to achieve the properties required. With knowledge of the composition and phase diagram, heat treatment can be used to adjust from harder and more brittle to softer and more ductile.

In the case of ferrous metals, such as steel, annealing is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air.

Copper, silver and brass can be either cooled slowly in air, or quickly by quenching in water.[1] In this fashion, the metal is softened and prepared for further work such as shaping, stamping, or forming.
What a great Duh moment this thread is.

 

[SEGARE]

^^^^^Wiki^^^^

 

[DonkeyHote]

In case anyone is interested, lot of good info from a metallurgist....

 

[tmwinds]

The effects of annealing at temperatures below which recrystalliza-
tion takes place may also be detected in the stress-strain curve. If a
specimen of brass is elongated by applying a load in tension, the elon-
gation is characterized by a rapidly and continually rising stress-strain
curve. If the load is removed and immediately reapplied, the second
application of stress rises to and continues to rise beyond the point of
interruption of the first cycle of stress; however, if the specimen is
annealed at a temperature below the recrystallization temperature,
appreciable yielding begins at a low value. Thus, a portion of the
initial strain hardening has been lost at the temperature and time of
anneal, and yet no recrystallization has taken place. The effects of
recovery are also detected in decreasing spring back under the in-
fluence of both time and temperature. The phenomenon of "season
cracking" in brass is mitigated by a low temperature recovery anneal,
and this treatment is regularly applied in industry to prevent this phe-
nomenon in cartridge brass. The magnitude of macro stresses is con-
siderably decreased, as evidenced by the partial return of elastic
properties to a condition intermediate between the cold-worked con-
dition and the fully annealed condition and the decreased tendency to
crack with further working. A condition refered to as malleability or ductility .
Complete stress relief is not attained by recovery, but is attained
by recrystallization. The mechanism of the phenomenon of recovery is
not understood, and probably will not be understood until the proc-
esses involved in plastic deformation are better defined. Recovery un-
doubtedly affects the elastic properties through the partial elimination
of internal stresses. The partial elimination of internal stresses also
decreases the internal friction, the electrical resistance and the velocity
of solution in acids, but has little effect on the strength and ductility
properties. The resolution of the alpha doublet in X-ray reflections is
regained, at least in part, during recovery anneals at temperatures
below recrystallization.
The perfection of atom disposition on a space lattice is grossly
distorted during plastic deformation; the atomic planes become twisted
and distorted, and the atoms no longer occupy precision positions
on a space lattice but are distorted to positions less symmetrically
disposed. This distortion results in an increase in the internal energy
of the metal, and a somewhat localized distribution of the energy.
The partial stress removal during recovery is probably associated with
a partial rearrangement of the space lattice, straightening of slip
planes, and return of atoms to positions more closely approximating
the unstrained space lattice. These processes are brought about by the
influence of heat, which permits a greater thermal vibration of the
atoms with resultant diffusion or movement of atoms to satisfy par-
tially the trend toward returning to the stable condition. The influence
of heat, however, is not great enough to permit a complete rearrange-
ment of the atoms on the space lattice, and the complete relief of stress
is not obtained.

Exactly what I was thinking. Couldn’t have said it better myself.

 

[JPB4BAMA]

As a degreed metallurgist, what are your thoughts on post #56?

A rather long drawn out explanation for the lay person but essentially correct. In simpler terms. Working of most metals or alloys (crystalline solids) below specific temperatures defines cold working vs hot working. In this region the working results in dislocations within the crystal lattice which as more and more dislocations form they interact with each other making it harder and harder for further deformation to occur. Think of one string of Christmas lights then think of many tangled together. This is cold working. Associated with this tangled mess is retained energy, the bigger the mess the more energy. Application of heat allows this mess to relax and reform. First is recovery where some of the mess just sort of untangles, second is recrystallazation where if inbound deformation and energy is there entire new and smaller grains form from the parent. Third is grain growth with sufficient time and temp the new smaller grains look to lower their energy state and coalesce into larger grains. This process is referred to as annealing, but is not limited to achieving all three stages, but based on the desired end state mechanical properties of wHich there are more than simply ductility.

So... although I am a ferrous metallurgist, and not an expert in Cu based alloys, it is my opinion that in the case of “annealing” resized cartridge brass (meaning only resizing brass from the as fired state to resized and not altering its original configuration) insufficient residual driving energy is present to effectively result in full recrystallization but more in line Recovery which “may” provide some ductility benefits and likely extension of brass life as opposed to repeated working without the anneal.

I personally do anneal, but primarily for the purpose of brass life I believe at least empirically that it helps. As far as improving on paper results I defer to those much more skilled than myself, but will offer for academic debate the study performed by Bryan Litz where at least in a limited DOE no conclusive benefits were noted to be significant, tempered with the understanding that it must be intuitively obvious that minimizing variations in as many factors as possible has to be a good thing when striving for consistent and repeatable results.

 

[holstil]

I was considering trying to become a Japanese sword making apprentice,,,but now,,,?

Tempering anybody?

Prolly better time spent climbing the Himalayans looking for a bell to ring.

 

[jackieschmidt]

This whole string just brought a smile to my old face. I won’t directly comment on what terminology is actually correct as that is irrelevant within confines of the audience who may actually participate in the subject activity.

But out of a nagging sense of curiosity I am interested to know who else here, besides myself is actually a Metallurgist by degree?

I am not a metallurgist by degree, but being in the Machine Shop Business most of my life, I have gained a fairly thorough knowledge of material specifications as they relate to various applications.

There is a lot of misinformation and statements in this thread that are just not correct. But I find it unproductive to challenge others in a Forum such as this when it comes to the technical side of how different metals respond to various heat treating and cryogenic procedures.

Practical application is a different story. in particular when it comes to the different steels used in the manufacturing of the various parts that make up a firearm.

 

[johnfred1965]

A rather long drawn out explanation for the lay person but essentially correct. In simpler terms. Working of most metals or alloys (crystalline solids) below specific temperatures defines cold working vs hot working. In this region the working results in dislocations within the crystal lattice which as more and more dislocations form they interact with each other making it harder and harder for further deformation to occur. Think of one string of Christmas lights then think of many tangled together. This is cold working. Associated with this tangled mess is retained energy, the bigger the mess the more energy. Application of heat allows this mess to relax and reform. First is recovery where some of the mess just sort of untangles, second is recrystallazation where if inbound deformation and energy is there entire new and smaller grains form from the parent. Third is grain growth with sufficient time and temp the new smaller grains look to lower their energy state and coalesce into larger grains. This process is referred to as annealing, but is not limited to achieving all three stages, but based on the desired end state mechanical properties of wHich there are more than simply ductility.

So... although I am a ferrous metallurgist, and not an expert in Cu based alloys, it is my opinion that in the case of “annealing” resized cartridge brass (meaning only resizing brass from the as fired state to resized and not altering its original configuration) insufficient residual driving energy is present to effectively result in full recrystallization but more in line Recovery which “may” provide some ductility benefits and likely extension of brass life as opposed to repeated working without the anneal.

I personally do anneal, but primarily for the purpose of brass life I believe at least empirically that it helps. As far as improving on paper results I defer to those much more skilled than myself, but will offer for academic debate the study performed by Bryan Litz where at least in a limited DOE no conclusive benefits were noted to be significant, tempered with the understanding that it must be intuitively obvious that minimizing variations in as many factors as possible has to be a good thing when striving for consistent and repeatable results.

Thank you, Sir. As a lay person that was a clear and easily comprehended explanation. As it applies to the majority of members here who are not in the field, probably much more useful and informative. If I have understood properly, what we do to brass is recovery annealing, but a type of annealing none the less, and recrystalization is not necessary to have benefits for the shooter.

 

[JMayo]

Hummm, as i push my black framed, with taped nose bridge, up from the tip of my nose .....

The revelry of knowledge here... Impresses me so much ....

LMFAO !

 

[JPB4BAMA]

Thank you, Sir. As a lay person that was a clear and easily comprehended explanation. As it applies to the majority of members here who are not in the field, probably much more useful and informative. If I have understood properly, what we do to brass is recovery annealing, but a type of annealing none the less, and recrystalization is not necessary to have benefits for the shooter.

That is essentially correct given that the sizing operation is minimal and the annealing process frequent. Otherwise the repetitive or excessive cold working can and does lead to excessive material hardening that will lead to failure such as cracked necks.

I must also refer back to post 90, where as Mr Schmidt accurately points out that the practical application may differ from the theoretical textbook explanation. I was trying to also convey this in the final portion of my post: I hope that was not lost in my monologue. If so my apologies to all.

Bottom line is do what you reasonably feel assist in achieving your end goal, if noting else it adds to the feeling of confidence which in of itself is a positive benefit.

Thanks