Synergistic regulation of microstructure,properties,and abrasive wear mechanism of a medium carbon dual phase steel for plowshares

In this study, a new medium carbon dual phase (DP) steel for plowshares is prepared. The quenching and partitioning process of the medium carbon steel is designed and optimised using the constrained carbon equilibrium model. The optimised process parameters are quenching temperature of 880 °C, quenching bath temperature of 190 °C and partitioning temperature of 350 °C. The microstructure of the acicular martensite matrix with 13% retained austenite was prepared, so that the good mechanical properties of tensile strength of 2007 MPa, yield strength of 1689 MPa, elongation of 11% and impact energy of 12 J are obtained. The multi-scale characterisation and abrasive wear experiments are carried out to investigate its microstructural evolution and wear mechanism under simulated working conditions. The results show that the coordinated deformation of retained austenite and martensite, as well as the trip effect, endows it with ultra-high strength and good plasticity. The recurring process of formation and spalling of the hardened layer is the main wear pattern of this medium carbon DP steel. The synergism of twinning formation and (Ti, Mo)C precipitation enhances wear resistance of this medium carbon DP steel.