Thread: Cooked my brass, Whoops

Originally Posted by Puffin

@Feather or Shoot I recently came across the following:
http://web.nchu.edu.tw/~jillc/me/Ch1...0Treatment.pdf
Pages 33-37

That's some confusing stuff @Puffin!

I get that softening happens during the re crystallization temperature boundaries of 200& 500°C. I don't get how they don't show time on that graph. They then refer to the annealing of brass at 580°C being totally re crystallized after 8 seconds.
Interesting that the more worked brass is the less temperature it takes to anneal.

In the steel section they talk of age hardening at low temperatures for long times, I wonder if brass age softens when treated the same.

Any idea what hardness we are aiming for when annealing cartridge brass?

Sent from my GT-I8190T using Tapatalk

i'd think they'd be ok?
they are never going to hold in the pressure, that's the job of the chamber/bolt, they might be soft to resize without collapsing till hardened again tho....


oops, just saw Shearer's post after skimming to the bottom.... I'm with him
oh, and the anneal temp looks like 250c in that graph, for some kinda brass.....
reach temp, hold for time of choice to be certain chrystals are aligned, then cool at some rate that doesn't bring in more stresses....
brass harden with work, steel by quick cool to lock in new Chrystal structure.

Originally Posted by Awaian

i'd think they'd be ok?
they are never going to hold in the pressure, that's the job of the chamber/bolt, they might be soft to resize without collapsing till hardened again tho....


oops, just saw Shearer's post after skimming to the bottom.... I'm with him
oh, and the anneal temp looks like 250c in that graph, for some kinda brass.....
reach temp, hold for time of choice to be certain chrystals are aligned, then cool at some rate that doesn't bring in more stresses....
brass harden with work, steel by quick cool to lock in new Chrystal structure.

Wouldn't the shoulder crush when resizing, Primer pocket expand, and neck run into the throat on firing?

Sent from my GT-I8190T using Tapatalk

yes for resize, not sure about the rest, possible?
load light.... suck n see
or scrap em, get more, don't multitask till after the new skirt purchase cos you're not designed for it.

Dont know if this will help, its from a 1964 lyman book basically as I read it, a case annealed to the same crystal structure right through is not a good thing, but forrm your own opinion.

nice info, thanks Marty Henry, flat out says its stuffed (when case completely annealed).

also like to apologise if my flippant comments don't get received well. (ie last post), sometimes can be a bit blokey and i realise we don't all know each other so well.

Originally Posted by Marty Henry

Dont know if this will help, its from a 1964 lyman book basically as I read it, a case annealed to the same crystal structure right through is not a good thing, but forrm your own opinion.

Weirdly, it says the neck needs to be harder than the rest. But those small crystals tell me it's softer than the rest.

😥

Sent from my GT-I8190T using Tapatalk

So are none of you quenching? Critical part of annealing....

Originally Posted by Wirehunt

So are none of you quenching? Critical part of annealing....

For steels, not for brass according to the literature.

Originally Posted by Shearer

Where do people think they would fail? They are encased by a solid metal chamber and can only expand as far as that allows. After all it is not the brass itself that contains the pressure is it. It is the bolt face at the rear and the barrel surrounding the case????? Will it split at the neck? Be extracted in two pieces?

Not completely unfortunately. The head around the perimeter for the few millimetres where it emerges from the chamber - from the upper edge of the extraction groove back - is not supported. I have brass from this part of a case embedded in various parts of me so would encourage everyone here to err on the side of caution when it comes to things that might affect case heads.

Originally Posted by Feather or Shoot

That's some confusing stuff @Puffin!

I get that softening happens during the re crystallization temperature boundaries of 200& 500°C. I don't get how they don't show time on that graph. They then refer to the annealing of brass at 580°C being totally re crystallized after 8 seconds.
Interesting that the more worked brass is the less temperature it takes to anneal.

In the steel section they talk of age hardening at low temperatures for long times, I wonder if brass age softens when treated the same.

Any idea what hardness we are aiming for when annealing cartridge brass?

Sent from my GT-I8190T using Tapatalk

Agree. I'm assuming that time is fixed, but no figure has been given, and then the crossing of the data plots in figure 10-33 is unintuitive. Also online searches reveal a differing in opinion over whether low temperature "age" annealing is possible. If I was sufficiently motivated I'd spend a day up at the VUW library trying to get to the bottom of it as it is in the area of my educational background, but my DIY inductive annealer has recently appeared to result in a halving of vertical dispersion out to 1000 metres so I'm content at the moment to engage in casual reading on the topic, follow the debate in an ill-informed manner, while enjoying the practical benefits !

once at temp it's done.
a soak is held to be sure all the object of interest has time to be affected evenly, so some tens of minutes depending on the heating implement.
flame/oven etc and metal thickness/mass

Originally Posted by Puffin

Agree. I'm assuming that time is fixed, but no figure has been given, and then the crossing of the data plots in figure 10-33 is unintuitive. Also online searches reveal a differing in opinion over whether low temperature "age" annealing is possible. If I was sufficiently motivated I'd spend a day up at the VUW library trying to get to the bottom of it as it is in the area of my educational background, but my DIY inductive annealer has recently appeared to result in a halving of vertical dispersion out to 1000 metres so I'm content at the moment to engage in casual reading on the topic, follow the debate in an ill-informed manner, while enjoying the practical benefits !

Always wanted to do a DIY induction annealer. Where'd you get the parts and plan from? Or is this original puffin magic?

Sent from my GT-I8190T using Tapatalk

We always did this old school, container of water at the right level on the cases, get to the right colour with the gas torch, a shake to quench. I'd say the commercial outfits are doing the same going by the case colour when you get them.