Enhancing mechanical properties and wear resistance of heavy-haul rail systems through complex microstructure control
Dany Michell Andrade Centeno, Gustavo Tressia, Felipe M. Carvalho, Fabiano Eduardo Marques Cezario, Edwan Anderson Ariza Echeverri, Mohammad Masoumi
Abstract
This study delves into the formulation of an advanced microstructure in medium-carbon high-silicon spring steel through a series of engineered heat treatments. The microstructure, composed of lower bainite, proeutectoid ferrite, and pearlite, exhibits superior mechanical properties compared to traditional pearlitic steel. Specifically, the novel microstructure yields a strength of 870 MPa and an ultimate tensile strength of 1050 MPa, along with an enhanced total elongation of 9.75%, while the pearlitic steel achieved a yield strength of 745 MPa, an ultimate tensile strength of 845 MPa, and a total elongation of 9.0%. The steel’s heightened strength is attributed to dislocation and precipitation strengthening, with the proeutectoid ferrite at grain boundaries contributing to the excellent elongation. The study thus establishes a groundbreaking and readily implementable heat treatment process that significantly boosts the performance and longevity of heavy-haul rail system, owing to the synergistic contribution of lower bainite, proeutectoid ferrite, and pearlite in the microstructure.