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Old August 20, 2019, 11:44 AM   #51
Unclenick
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Join Date: March 4, 2005
Location: Ohio
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The Kline study has a plot for time required to initiate recrystallization vs. temperature for both 50% and 75% CW brass. The time threshold varies exponentially, roughly halving every 33K for the 75% CW, for which the function made a nice straight line when the time axis is on a logarithmic scale, but not being such a simple function for the 50% CW brass. It gives about 6 seconds (0.1 minutes on the graph) for about 833K, or about 535°C, which is 995°F.

However, other charts he has show hardness starting to change before recrystallization actually commences. Even 100°C cause some change in the yield point over a period of a week. And, get this, the hardness and yield bottom in some plots at about 30 minutes exposure, and goes up again when it is drawn out to 60 minutes. This is explained by an accumulation along the enlarged grain boundaries of, IIRC, nucleation points. I'll have to reread that.

In any event, this is not nice neat all-else-being-equal parallel predictable behavior.
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