On Tuesday 02 August 2016 13:09:06 Mark wrote: > On 08/02/2016 12:39 PM, Gene Heskett wrote: > > On Tuesday 02 August 2016 10:46:03 Mark wrote: > >>> Silly Q: Going online to the metals pedlars, C360 seems to be what > >>> 90% of the bar stock offered is. But regardless of the alloy, its > >>> all stated as not being heat treatable. Since extruded brass is > >>> called half-hard, or HO2, it can be played with in the oven (if > >>> its hot enough), but always to soften. > >>> > >>> Are they simply trying to head off the idiot that thinks ferrous > >>> and wonders why his stock is dead soft after he heat treated it > >>> like steel? > >>> > >>> Cheers, Gene Heskett > >> > >> Gene, > >> > >> You can't "heat treat" brass/bronze/copper etc (non-ferrous) to > >> harden. You can only anneal those metals. They do, however, work > >> harden, which annealing takes away. > >> > >> Mark > > > > I know that, Mark. For many decades. :) > > > > Cheers, Gene Heskett > > Perhaps I'm not understanding your earlier questions then about heat > treating? > > > Mark
Heat treat in this context is "low temp" soaking at 475-525F for 1/2 to one hour, which relieves the stored stress from the original extrusion process. This is why, when one goes to saw a strip off the edge of a bar, the kerf opens up and both sides of a straight line are badly warped, sometimes in all 3 dimensions. My 4+ hours at a hair above 400 in a toaster oven helped, a lot, but was not enough. We'll "adjust" the toaster oven before we power it up for the next part. With two IR tubes in it, I figure there's at least another 150-200 degrees available. Then if you want to anneal it, totally getting rid of the work hardening it did while being extruded, or while you were hammering it into shape to make something artistic, another temperature range comes into play starting at around 710F where its not only stress relieved but the work hardening from its previous forming operations is also cooked back out and in an hour or so you will have dead soft brass again. The only way to harden it again is by hammering and bending it. Around 1650F will melt it so you can pour a sand casting. Which will be dead soft when the sand is washed off. And now you know about as much as I do about brass. There seems to be a certain amount of alchemy in the alloying of brass, not all of which is readily available on the innertubes. And I can truthfully say that at 81, I am not the man I once was, but I claim I am that man once. I just replaced one of the two fenceposts that have rotted off in the lower run of our split rail fencing. Over a decade old, but thats all that have failed so far. Ignore that faint knocking sound as you know what it is. ;-) Whether I can do the other tomorrow, weather permitting, remains to be seen. 19:40 locally, must be beer-thirty. But first I'd better go see if a grocery list has materialized. Cheers Mark & everybody, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
