Normalizing is a heat treatment process used to relieve internal stresses, refine the steel grain size, refine the steel grain structure and improve the mechanical properties of 52100 steel. Normalizing is done to give the steel a uniform and fine-grained structure prior to the induction heat treating of the roll surface. The normalization process significantly improves the ductility, toughness and increases the strength/hardness of the steel. The core hardness after normalizing is 26-30Rc. Additionally steel that has been normalized allows for an increased induction heat treated roll surface depth and a more gradual transition from high hardness to core hardness (64Rc – 26Rc).
Rolls that are made from Normalized 52100 steel are significantly stronger, more ductile, have increased wear life and are much less prone to spalling.