Brass Hardening

[Chris TriceParticipant @christrice43267]

When I silver solder brass tube together, it's obvious that it's been annealed (softened) by the ease with which the tube can be bent but did I read somewhere that the brass will slowly harden again over time or is there a process I don't know about for hardening brass?

Edited By Chris Trice on 10/08/2012 00:59:42

[Chris TriceParticipant @christrice43267]

[John Stevenson 1Participant @johnstevenson1]

Years ago brass was hardened by heating up to cherry red and quenching into the blood of a 16 year old virgin.

Given the current state of play, chances are it will be a long time before we see and hard brass again.

 

John S.

Edited By John Stevenson on 10/08/2012 01:14:04

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Chris ,

Ordinary engineering grades of brass will age harden in a few weeks to a few months . Time depends on cross section .

High zinc content brasses and ones with added lead don't age harden .

Some poor quality 'yellow' brasses can crystalise over time and crumble away .

There is no way of hardening brass by heat treatment . Cold working (ie forging) will harden brass but this is usually impractical on machined parts .

Sheet brass for ornamental work is often planished both to improve the surface appearance and to harden the metal .

Regards ,

Michael Williams .

[macmarchParticipant @macmarch]

All brass will develop stress when worked.

Always leave a small radius at the bottom when turning down.

Bend sheet slowly to allow the stresses to flow. Then heat to dull red and quench in water or leave to cool. This will prevent season cracking and early failure. Look at "season cracking" on wikipedia etc.

ray

[Sub MandrelParticipant @submandrel]

When punching a lot of small holes in some brass sheet, I found it hardened noticeably overnight when i annealed it but didn't try and work it until the next day.

neil

[Chris TriceParticipant @christrice43267]

Thanks for all the replies. I've had a similiar experiences when just after annealing, the brass is clearly very soft and easy to manipulate but it seems much harder the next day. I'm glad I wasn't imagining it.

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