Study on wear behaviour of 4Cr4Mo2NiMnSiV die steel at high temperature

Abstract In this paper, with reference to the composition and properties of widely used H13 hot working die steel, and the amount of alloying elements in the steel is reasonably improved, and a new steel grade of 4Cr4Mo2NiMnSiV die steel is designed. A new process was designed and the wear properties of 4Cr4Mo2NiMnSiV die steel were studied. SEM, EDS and XRD were utilized to observe the microstructure of the worn surface, and the wear products were analyzed to discuss the wear mechanism. Conclusion illustrates the coefficient of friction of cast steel 4Cr4Mo2NiMnSiV gradually increases with increasing temperature. Wear of the 4Cr4Mo2NiMnSiV die steel is mainly caused by spalling and high-temperature oxidation. The surface oxidation products of high temperature wear samples are Fe2O3 and Fe3O4, and spalling debris caused by fatigue cracks is blocky and a small amount of long flake oxide. The oxide film generated during the high temperature wear process effectively reduces the wear of the material. Through comparison experiments, it is found that the 4Cr4Mo2NiMnSiV die steel of martensite and bainite structure has the best wear resistance, followed by martensitic alloy steel, and the wear resistance of H13 steel which is involved in comparison is lower than that of alloy steel.