Full pearlite obtained by slow cooling in medium carbon steel

Fully pearlitic steels are applied widely in engineering structures in the form of strong cables. They conventionally contain 0.8 wt% of carbon and therefore can be poor in ductility. One solution is medium carbon steel but which is fully pearlitic. This can be achieved only by rapid cooling which is not convenient for commercial manufacture. In the present work an almost fully pearlitic microstructure was designed in a 0.4 wt% carbon containing steel, in the as-cast condition, by slow cooling. The mechanism involves the suppression of allotriomorphic ferrite formation from austenite during casting because of the big austenite grain size. Fine divorced-cementite lamellae formed in pearlite due to the huge driving force.

Research highlights▶ An almost fully pearlitic microstructure was designed in a 0.4 wt% carbon containing steel. ▶ Fine divorced-cementite lamellae formed in pearlite due to the huge driving force. ▶ Huge chemical driving force is due to state transition from non-equilibrium to equilibrium.