At what temperature is steel typically heated for an annealing process?

The temperature at which steel is typically heated for the annealing process is just above the transition temperature. Annealing is a heat treatment process that involves heating the metal to a specific temperature, holding it there for a certain period, and then cooling it down slowly. This process helps to soften the steel, relieve internal stresses, improve machinability, and refine the grain structure.

The transition temperature refers to the point at which steel transitions from a harder, more brittle phase to a softer, more ductile phase. Heating just above this temperature allows for optimal absorption of the heat treatment benefits without risking the structural integrity of the steel. If steel were heated below the transition temperature, it would not achieve the desired softening effect. Conversely, heating above the melting point would cause the steel to lose its solid form entirely. Thus, the choice of heating the steel just above the transition temperature is crucial for achieving the desired properties through the annealing process.