高铬铸铁性能研究毕业论文

This paper uses a TypeXJP-3 metallographic microscope, HV-100 microhardness tester, ZEISS opticalmicroscope, impact tester and other analytical instruments, fully investigatesthe microstructure and integrated mechanical properties, such as tissuestiffness, impact toughness of the high chromium cast iron after heat treatmentprocess. The experimental results obtained show that the high-chromium castiron after heat treatment has superior integrated mechanical properties, suchas hardness, impact toughness, than those of non-treated one, mainly due to thephenomenon that most fraction of the material tissue of the high-chromium cast iron after heat treatment hasbecome martensite matrix substrate from austenite, thereby having less austeniteand increasing the hardness of high chromium cast iron tissue, also improvingthe morphology of eutectic carbides, weakening the cutting and destructing between the matrix organization, thereby decreasing the fracture of the matrix tissue and increasing the impact toughness of high chromium cast iron. The microstructures obtained using heat treatment process are less different, consisting of martensite + carbide + austenite, whose ingredients are different. When the original primary austenite is heated, the effect of quenching will decomposecertain secondary carbide, and the precipitation amount of the secondarycarbides is significantly affected by different quenching temperatures. As known from experimental analysis comparison, as the quenching temperature rises, thedecomposition amount of secondary carbides is decreasing gradually, but the particles becomes coarse gradually; when the quenching temperature decreases, the effect is reversed compared with above.