tomcat818
Member
Complete Annealing is carried out by heating above the upper critical temperature, and then cooling slowly in a very controlled manner. It requires complete knowledge of the isothermal transformation diagram and the cooling transformation diagram of the alloy so that the desired microstructure of the alloy is achieved.
This came to mind after watching many videos on annealing brass and realizing there was little to no discussion about cooling time other than ambient cooling or dropping brass in water. Some compared non-virgin annealed brass with no regard to cooling to non-annealed non-virgin brass while monitoring seating pressures and discovered the annealed brass had more pressure standard deviation than non.
Heating the alloy is just the first step and does not constitute annealed brass since there is no controlled\timed cooling process. In the glass industry these temp over time controlled ovens are called annealing ovens and the glass (heated to ~2,400F) takes ~ 14hrs to be brought down to room temp in these ovens so it is not overly brittle.
I understand this topic may be more suited to the bench rest crowd but with the prices being charged for quality brass these days I would love to get more firings while maintaining accuracy.
I'm asking these questions because I've reached the customary 2-3 firings were some believe annealing should take place on ~150 pieces of brass (100 Petersen which came annealed, 50 Nosler Premium which did not). I want to make the most informed decision possible before plunking down a bunch of money to implement this process.
Anyone utilizing a controlled cool down in their brass annealing process?
This came to mind after watching many videos on annealing brass and realizing there was little to no discussion about cooling time other than ambient cooling or dropping brass in water. Some compared non-virgin annealed brass with no regard to cooling to non-annealed non-virgin brass while monitoring seating pressures and discovered the annealed brass had more pressure standard deviation than non.
Heating the alloy is just the first step and does not constitute annealed brass since there is no controlled\timed cooling process. In the glass industry these temp over time controlled ovens are called annealing ovens and the glass (heated to ~2,400F) takes ~ 14hrs to be brought down to room temp in these ovens so it is not overly brittle.
I understand this topic may be more suited to the bench rest crowd but with the prices being charged for quality brass these days I would love to get more firings while maintaining accuracy.
I'm asking these questions because I've reached the customary 2-3 firings were some believe annealing should take place on ~150 pieces of brass (100 Petersen which came annealed, 50 Nosler Premium which did not). I want to make the most informed decision possible before plunking down a bunch of money to implement this process.
Anyone utilizing a controlled cool down in their brass annealing process?
