Effect of phosphorus as an alloying element on microstructure and mechanical properties of pearlitic gray cast iron

This research investigates the effect of phosphorus as an alloying element on microstructure, eutectic temperature, hardness and mechanical properties of gray cast iron. Five different amounts of phosphorous (0.5, 1, 1.5, 2 and 2.5 wt%) have been added. Results show that increasing phosphorous from 0.45 to 2.58% in gray cast iron increases the amount of eutectic phosphide from 4.7 to 17.81%, weakens mechanical properties (tensile strength reduced from 297.5 to 184.1 MPa, impact strength from 4.3 to 2.7 J), increases hardness from 215.43 to 249.38 and lowers the eutectic temperature from 1139.7 to 1102.5 °C.