Jul 28, 2022 · Process: Heat the steel above Ac3 20 ~ 30 ℃, heat preservation for a period of time after slow cooling (along with the furnace) to get closer to the balance of the heat treatment process (completely austenitizing). The total annealing is mainly used for subeutectic steel (wc=0.3~0.6%), generally medium carbon steel and low, medium carbon alloy steel castings, forgings and hot rolled profiles, and sometimes used in their welds.