Hot metal / cold metal

[Patricklaw]

Can anyone help me understand why, when I drop my newly cast rifle bullets from the mold into cold water to quench them it makes them harder but when I heat the top half of my rifle brass and quench it in cold water it makes the brass soft and workable?

Yes, I know it's a noob question and I should know better but I must have been out for that day of class.

[Lizard333]

Quenching lead and brass are totally different. Brass does not harden like steel when it is quenched. You can cool brass quickly or slowly. No difference. The crystalline structure doesn't realign like steel or lead.

[runfiverun]

ferrous and non ferrous metals act differently.
you work soften lead and work harden brass.
you heat to cold quench lead/antimony alloys to harden it.
you heat up copper zinc alloys to soften them, quenching them has no affect on the anneal.

[Patricklaw]

Thanks for the help guys. It works like I thought it did.

[Defcon-One]

Just a note: You can't harden pure Lead by water quenching it. It must be an alloy with Antimony in the mix (1%-6% Sb is typical). The Antimony is the hardening agent and where the enhanced grain structure comes from. Adding a tiny bit of Arsenic helps with the hardening as well, I believe that it is acts as a grain refiner (It is found in COWWs). Tin ads maleability and toughness. They all work together!

You probably knew that, but it bears mentioning here.