Influence of Microstructure on the Mechanical Properties of a Pearlitic Steel

The effect of austenite grain size on microstructure and mechanical properties was studied for a pearlitic steel. The best combination of ultimate tensile strength (UTS) and percent reduction in area (pct RA) was obtained when the material was austenitized at 950 °C, and the corresponding austenite grain size, before the start of cooling, was approximately 71 μm. Pearlite lamella spacing and colony size were minimum for these samples. Both UTS and pct RA were found to maintain a kind of power law-type relationship with microstructural aspects such as pearlite lamella spacing and colony size. The experimental data suggest that further enhancement of the strength of prestressed concrete (PC) wire rod (beyond 1200 MPa) would require a fine pearlitic microstructure in which pearlite lamella spacing would be below 0.05 μm and average colony size would be below 4 μm.