You cannot anneal at 750/800F. you may be stress relieving. You need to be at about 1050/1100F to anneal. The neck should just turn red for 1-2 seconds.
When I look at the charts I compare 15% cold work reduction in thickness to the several temperatures. It seems like a good guess at % cold work since we don't know the actual %. The trends are what I look at rather than the actual numbers. The next chart in the report was 600C=1112F this is much higher than I want. The shortest time in the study was 15 seconds at temp in a lead bath. The sample had thermal couples on them and time was time at temp
What I see is practically nothing happens at 15 seconds at temp at temp in a lead bath.
There are many scales for reporting hardness this study used the Rockwell H scale. The cold work was achieved by cold rolling a small plate about 1/8" thickness to various thicknesses. Don't jump on they are not cartridges. The numbers basically give you an idea of what's going on.
Results:
15% cold work 30 seconds at 842f showed a .8 RH increase. 10% cold rolled showed 2 unit decrease. Probably within the error because they are different pieces of metal even though they were processed under similar conditions.
1/2 hr at temp before grain size changes.
450C=842F
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550C=1022F
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Below are the results of my annealing study done at work on cartridge necks annealed in a small laboratory accurate furnace. I chose 15 sec hold time in the furnace since I didn't know how long it took the neck to reach temp. 5 minutes at 800F the hardness only dropped about 2 units HRB sale.
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