Open Fire Normalizing
Also used to soften and relieve internal stresses after cold work and to refine the grain size and metallurgical structure. It may be used to break up the dendritic (as cast) structure of castings to improve their machinability and future heat treatment response or to mitigate banding in rolled steel. This requires heating to above the As temperature, holding for sufficient time to allow temperature equalization followed by air cooling. It is therefore similar to annealing but with a faster cooling rate. NATIONAL HEAT TREAT has 2 furnaces capable of performing this process.