Annealing, how often

An article I found.



"
This is what I learned working with cartridge brass ( 70 Cu- 30 Zn).

• All brass of the same grade is not the same when specifying annealing temperature
• Most yellow brass is manufactured from recycled brass, aka scrap
• The use of recycled brass introduces impurities of iron, lead, tin, phosphorus . and others
• Whne brass is annealed , it recrystallizes to an initial grain size that is dependent on the cold work in the brass along with prior in process hot anneals ( grain size) and purity.
• Although brass with low imputities and sufficient cold work will recrystallize ( anneal) at 370 C. , it was common to anneal cartridge brass at 500C or higher to meet unique grain size requirments for shellcase.
• To adjust for impuity levels in the brass, the brass was reclassified after melting and casting into sub categories ( about 5 ) for t purpsoe of specifying annealing parameters
• The annealing temperature required to achieve uniform grain size varied by nearly 100 degrees C dependent on the impurity level
• In the special case of a phosphorus impuity of greater than 0.001% in the presence of iron, we would bnot use this grade for shellcase as the annealing repsonse was very unpreditcable for the shellcase grain size specifications
  • There are other things we learned and applied that iI dont need to reveal - need some secrets.

I suspect brass is stil mostly manufactured from recycled brass with impurites , so I can see the annealing temperature requirement can vary from lot to lot and the degree of the anneal as measured by grain size will vary by prior cold working… from 370 C. for high purity heavily cold worked brass to 600 C, for recycled brass loaded with iron up to 0.1% and phosphorous over 0.001%."

Makes me think that the more you aneal the less heat is needed to achieve full aneal( less work hardening between anneals). Also makes me think temp is not as critical as some believe

Interesting info jasent. From what I understand annealing is also a function of time and temp. More heat less time, less heat more time. The more time less heat option doesn't work well with cases because it wiil end up annealing the whole case.

jasent how do you gage the temp and time to do your annealing?

Just by feel now( temp at the head where it touches my fingers). I used to do it in the dark and watch for the glow. But after doing this for years you can do it in your sleep. Also by sight. Brass starts it rapid oxidization starts to occur around 550f. This is the colors you see run down the neck and shoulder. When I see the colors run to the shoulder I quite and it dosent travel much after removing from the flame. What colors you see depends on amount of oxygen in the flame.

Also keep in mind that 550 depends on brass quality could be a bit more or less. Also anything behind that color line is hotter than the temp needed for rapid oxidization(color change)

jasent said:

Brass starts it rapid oxidization starts to occur around 550f. This is the colors you see run down the neck and shoulder. When I see the colors run to the shoulder I quite and it dosent travel much after removing from the flame.

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This is what I do. Just watch the color run down the neck and shoulder.

Read this recent thread to learn more:

https://www.longrangehunting.com/th...s-torch-head-annealer-vs-2nd-3rd-shot.199362/

Dr. Vette said:

Read this recent thread to learn more:

https://www.longrangehunting.com/th...s-torch-head-annealer-vs-2nd-3rd-shot.199362/

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interesting thread thanks for sharing.
Pic is my load on the brasses 16th loading

jasent said:

Also keep in mind that 550 depends on brass quality could be a bit more or less. Also anything behind that color line is hotter than the temp needed for rapid oxidization(color change)

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I didn't take into account the quality of brass variable when looking at annealing but it makes sense that that is a factor.
I did research on metallurgy, and with brass, annealing was broke down to time and temp. It was broke down like 750 degrees for 1 second and say 600 for 2 seconds etc. Don't quote me on the exact temp and time because I went with the 750 so I don't remember the rest of them precisely.

jasent said:

View attachment 93966 interesting thread thanks for sharing.
Pic is my load on the brasses 16th loading

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That is impressive, you are obviously doing a lot of things right.

A question I have about annealing is. I see guys that anneal there brass then drop them into water right away to cool it down quick. One guy went so far as to say he get the brass glowing then puts it in cold water.

How many practice this? Just the simple thing of heating the brass to anneal it then putting it in water to cool it down?

IMHO you are loosing what you are after. That how we temper steel or metal in general to make it harder. Would that not do the same thing with the brass?

NEMTHunter said:

A question I have about annealing is. I see guys that anneal there brass then drop them into water right away to cool it down quick. One guy went so far as to say he get the brass glowing then puts it in cold water.

How many practice this? Just the simple thing of heating the brass to anneal it then putting it in water to cool it down?

IMHO you are loosing what you are after. That how we temper steel or metal in general to make it harder. Would that not do the same thing with the brass?

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From everything I've read if you heat brass to the point of "glowing" you're way over annealing

NEMTHunter said:

A question I have about annealing is. I see guys that anneal there brass then drop them into water right away to cool it down quick. One guy went so far as to say he get the brass glowing then puts it in cold water.

How many practice this? Just the simple thing of heating the brass to anneal it then putting it in water to cool it down?

IMHO you are loosing what you are after. That how we temper steel or metal in general to make it harder. Would that not do the same thing with the brass?

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steel yes. Brass no. I too dabble in metallurgy as I'm a hobby blacksmith. I have forged brass but if you get it too hot(passed glowing) it can crumble but if you heat it past crumble it melts. The thought is too cool it before it anneals the case walls near the head. Basically when we anneal we are tempering out the work induced stress

jasent said:

The thought is too cool it before it anneals the case walls near the head.

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Using my Bench Source machine I've played with junk brass just to see what would happen. I've put Tempilaq on it all the way down and then went ahead and fried that brass for several seconds. I have yet to see Tempilaq change/evaporate even halfway down the case when doing this despite the case mouth glowing red at the time.

I would suggest that the water does nothing useful, and that has been posited on this board previously.

Dr. Vette said:

Using my Bench Source machine I've played with junk brass just to see what would happen. I've put Tempilaq on it all the way down and then went ahead and fried that brass for several seconds. I have yet to see Tempilaq change/evaporate even halfway down the case when doing this despite the case mouth glowing red at the time.

I would suggest that the water does nothing useful, and that has been posited on this board previously.

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I would agree. Plus you have to dry the brass. Pain in the rear