Effect of Casting Pressure on Microstructure and Anti-abrasion Property of KmTBCr26 White Cast Iron

The use of liquid die forging technology for alloy casting can optimize the solidification structure and improve the mechanical properties by changing the solidification parameters. The wear resistance of Fe–Cr–C white cast iron is limited by the coarse and continuous carbides present in the solidification structure. The morphology and distribution of theses carbides are related to the nature of the solidification parameters. This study compares the differing solidification structure morphology, carbide phase evolution and related mechanical properties of Fe–Cr–C white cast iron under atmospheric and pressure. The solidification behavior of Fe–Cr–C white cast iron under pressure control mechanism of eutectic structure and carbide is established. The KmTBCr26 (GB/T8263-2010) cast iron was prepared by liquid die forging at the pressure of atmosphere to 160 MPa. The microstructure and the morphology of the samples were analyzed by scanning electron microscope (SEM) and X ray diffraction (XRD). Finally, hardness, toughness and impact wear properties of the specimens were tested. Comparison of solidification structure morphology, carbide phase evolution and related mechanical properties of Fe–Cr–C white cast iron under atmospheric and pressure. The nucleation rate and the content of the carbides in the Fe–Cr–C white cast iron increased significantly with the lifting of pressure. At the pressure of 160 MPa, the volume fraction of the carbide in the hypoeutectic alloy is two times that of the atmosphere pressure, and the content of the carbide in the near-eutectic alloy increases by about 1.5 times. Increasing the solidification pressure can promote the transformation of carbides to more stable types, including reducing the content of M3C carbides and increasing the content of M7C3 in the alloy.