anneal

The process of softening metal. For ferrous metals, that is those containing iron , the process involves heating the steel up to its critcal temperature and then slowly cooling it. For non-ferrous metals such as brass, bronze , silver, gold, aluminum and the like, the process is exactly opposite. The metal is heated to the critical temperature and then quickly quenched in water, snow, urine, or oil. What annealing actually does on a molecular level is to allow the metal crystals to realign, moving them into their more relaxed state. When the metal is worked, the crystals are moved out of alignment, contributing to both hardness and brittleness. Practically, in the production of arms and armour the metal must be annealed as it is worked, otherwise the metal might stress enough that it will crack.