Softening Steel With Annealing
All metals come from the earth and are subjected to fire of various degrees to separate the impurities and produce the basic metal. This applies to all the metals we have in everyday use about us from the cutlery in the kitchen drawer to the taps and to car outside.
That is not necessarily the end of the story as variations can be achieved and different properties obtained with the addition of the two simple elements of fire and water. Take any of the major metals and alloys and with heat and cooling the structure is changed. For example, case hardening steel is a process of taking steel and heating it with carbon which infuses with the surface of the steel and whilst still very hot it is immersed in room warm water. The result is an object with a tougher and harder outer surface.
Annealing on the other hand involves heating the steel and allowing it to cool at a much slower and more natural way and the end result is the opposite of hardening but instead softening the steel as the diffusion of the atoms within the structureresults in a more ductile medium.
The making of fire is often used as a metaphor for the beginning of civilisation. The ability to create fire in some societies thousands of years ago was seen as sorcery. Imagine a man with the knowledge of creating fire with the use of two sticks or two flints travelling to a far place and introducing this skill to people who had never seen it done. It must have seemed like trickery or devilment.
With fire man created protection from beasts at night and warmth in the freezing nights. With fire over a period of time man learnt to get a high enough temperature to extract metals from the ground. Copper was almost certainly the first metal and evidence of this reveals that this occurred in Mesopotamia some eleven thousand years ago.
Whether you want annealing or hard casing or any of the other ten or so treatments for metals then take a look at http://www.heat-treat.co.uk and take your choice.