annealing

To anneal a metal is to soften it, refining grains and removing stresses, by holding it at (or about 100 degrees F higher than) its transformation temperature (the temperature at which grain structure changes), allowing carbon to redistribute uniformly throughout the metal. Steel with 0.83% carbon content has a transformation temperature of 1,333 degrees F. This is much lower than the melting point of 2,462-2,550 degrees F.