Another Metallurgy Question for the Experts

[Engineer1911]

I read an article claiming that summertime temperatures would "anneal" water quenched cast lead alloy bullets. The annealing temperature was in the range of 90°F to 120° F, outside temp to "closed garage" temp.

Is this true? I have stored unsized / unlubed alloy bullets in my garage for some time now. I keep lubed / sized bullets indoors under my reloading bench. I have had bullet lube melt off 'garage' bullets into a total mess.

 

[Blue68f100]

I have no idea, but thing it's too low of temp to effect the hardness of the lead. Like you said depending on lube it can cause a mess.

It can and will effect powder though over long period of time.

 

[Rule3]

I read an article claiming that summertime temperatures would "anneal" water quenched cast lead alloy bullets. The annealing temperature was in the range of 90°F to 120° F, outside temp to "closed garage" temp.

Is this true? I have stored unsized / unlubed alloy bullets in my garage for some time now. I keep lubed / sized bullets indoors under my reloading bench. I have had bullet lube melt off 'garage' bullets into a total mess.

But what is the relative humidity??

All my bullets are in the garage since forever, all lubed. They must be very very annealed!

 

[243winxb]

Air cooled, containing tin, get softer over time, years. Oven heat treated, water cooled, that have 2% antimony fully harden in 2 weeks & remain that way. https://www.totalmateria.com/page.aspx?ID=CheckArticle&site=ktn&NM=88

Hardness Stability. For most of the two-year period, the solution-treated specimens were harder than the quench-east specimens. Other investigations have also shown that alloys cooled slowly after casting are always softer than quenched alloys. The alloys with 2 and 4% Sb harden comparatively slowly, and the alloy containing 6% Sb appears to undergo optimum hardening.

As for lube melting off, get a different lube. To apply, a lube heater is needed for your sizer.


More lubes with 165F ratings. https://lsstuff.com/store/index.php?main_page=index&cPath=1&zenid=egfpjndg6asru05n8llf0neib0

I found the 50/50 to need an air temperature of 75F minimum, or a heater is needed.

 

[lightman]

I wouldn't expect garage or even outdoor summer temps to get anywhere near hot enough to anneal. But they will melt some lubes. I'm not a scientist and may totally off base.

 

[DMW1116]

I read an article claiming that summertime temperatures would "anneal" water quenched cast lead alloy bullets. The annealing temperature was in the range of 90°F to 120° F, outside temp to "closed garage" temp.

Is this true? I have stored unsized / unlubed alloy bullets in my garage for some time now. I keep lubed / sized bullets indoors under my reloading bench. I have had bullet lube melt off 'garage' bullets into a total mess.

That is true but it depends on the particular alloys used, how much of the different elements were added, and how things were treated immediately following casting. Lead and lead-tin alloys have the unusual property of being able to recrystallize at room temperature, typically taken as 75 degrees F. This means the annealing operation done to brass cases happens in lead and lead-tin mixes at room temperature (not really, but its close enough to use as an analogy here). The usual strengthening methods for other alloys may not work. Some aluminum alloys are "naturally aged" meaning they harden to a point at room/ambient temperatures, but ambient temperature is too high for many lead alloys and though they may harden initially, hardness may decrease with time at room temperature. Different element additions may slow, speed up, or even stop this sort of behavior in lead.

 

[Bearded Phil]

Since I'm getting into casting soon I've been reading up on the subject and actually just last night was covering the metallurgy of Pb-Sn-Sb mixes and how they harden over time or can be manually heat treated and quenched to increase hardness.

I don't have the link to download at hand but maybe somebody can post it. I believe it's called "Ladle to Ingot... A guide to casting". Something to that extent.

From what I recall of what I read that temp in your garage isn't going to be hot enough alone to harden your casts if you were to drop them in water. The Sb in your alloy would cause the casts to harden over time but I believe they will stabilize after a certain amount of time.

 

[AJC1]

The easiest explanation I have is look at the temperatures for lead heat treating. I don't belive based on that data ambient temps are an issue.

 

[kcofohio]

Since I'm getting into casting soon I've been reading up on the subject and actually just last night was covering the metallurgy of Pb-Sn-Sb mixes and how they harden over time or can be manually heat treated and quenched to increase hardness.

I don't have the link to download at hand but maybe somebody can post it. I believe it's called "Ladle to Ingot... A guide to casting". Something to that extent.

From what I recall of what I read that temp in your garage isn't going to be hot enough alone to harden your casts if you were to drop them in water. The Sb in your alloy would cause the casts to harden over time but I believe they will stabilize after a certain amount of time.

Here's the link.
http://www.lasc.us/Fryxell_Book_Chapter_3_alloySelectionMetallurgy.htm

 

[mdi]

Sounds like "internet wisdom" to me. I would suggest K.I.S.S. for a new caster ("The only way to learn to cast bullets is to cast bullets). I know there is the "I just wanna know" factor, but getting into deep theory can be confusing and crippling. My cast bullets perform the same 3 summers and winters (100 degrees+ down to 35 degrees). The biggest problem for me and tems of my stored cast id lube melting...

One of the best places for info on everything cast bullets in an every day format is https://castboolits.gunloads.com/. Also a good read is "From ingot to Target" https://www.marvinstuart.com/firearm/Manuals/Bullet Casting/Fryxell_Book.pdf