The object of annealing is either to grain refine, induce ductillity, stress relieve or a combination of these. Castings, forgings, sheets, wires and welded materials can be subjected to an annealing process. This process consists of heating the material to a predetermined temperature, possibly allowing it to soak at this temperature, then cooling it in the furnace at a controlled rate. For full annealing and normalising, the temperature for carbon steels is usually 30-40 c above the upper critical temperature. Essentially, the difference between full annealing and normalising is that in the case of the annealing process the material is cooled slowly in the furnace whereas for normalising the material is cooled in still air out of the furnace.