New (to me) Nork... couple of issues!

Pr589 said:
To geek out a bit...

Assuming the mild (low carbon) steel used in a casing, the affect of annealing will depend on the annealing temperature and the quenching method. High temperature annealing followed by a fast quench will result in a harder metal, than a low temperature annealing and/or a slow quench.

Heating steel causes the metal grains/crystals to grow (the longer the annealing the larger the grains). A high temperature anneal followed by a fast quench could (depending on how hot) result in the grains reforming into a smaller size, hardening the metal. A low temperature anneal over a long time, followed by a fast quench would freeze the large grains, resulting in a softer metal.

Note that the story gets more complicated for higher carbon steels, and even more-so when other alloying materials come into play.

Geek off.
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If you quench your steel after heating to above the austenitizing temperature that is not annealing. Annealing is extremely slow cooling.
 
Throttle_monkey1 said:
If you quench your steel after heating to above the austenitizing temperature that is not annealing. Annealing is extremely slow cooling.
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Eaxactly. If it's steel and it involves a quench, it's hardening. After hardening, if it involves holding at a low temperature, (under 500F), its tempering. If it involves being heated above critical temperature and then a long slow cool down, it's annealing.

Also about the split necks, the M14 will have a longer chamber, the steel case won't like it. Fire that ammo once and forget about the casings. It's cheap BLAM BLAM as far as I'm concerned. If you're really worried check the primer for signs of overcharge.

If you were handloading/reloading quality brass and splitting necks, then you'd have an issue.
 
Silverado said:
How come we quench brass case necks when annealing them?
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Brass is an alloy of copper. Copper anneals differently than steel. When copper work hardens, I heat it till it glows, and quench it quick and long. But I'm talking about copper sheet and bar, I've never annealed case necks, but will likely have to learn one day.
 
SoBored said:
Brass is an alloy of copper. Copper anneals differently than steel. When copper work hardens, I heat it till it glows, and quench it quick and long. But I'm talking about copper sheet and bar, I've never annealed case necks, but will likely have to learn one day.
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So I agree with both SoBored and Throttle...clearly these folks understand phase changes in steel. My point stands that when many folks talk about annealing, they don't differentiate between steel, brass, annealing temperature and the cooling process. Colloquially speaking of annealing, the process (depending on the particulars and the material) won't always result in more ductile metal.

Btw - who would have thought that the eutectic diagram for brass (copper-zinc) was so complex. Anyone know the approximate composition used for rifle brass?
 
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