Figure 1. An idealised TTT curve for a plain carbon steel. Cooling at different rates from point X, i.e. above the As temperature will develop very different microstructures, and therefore properties, ...

See Curve 2 in Figure 1. Figure 1. An idealised TTT curve for a plain carbon steel. Also used to soften and relieve internal stresses after cold work and to refine the grain size and metallurgical ...