The effect of carbon content on primary austenite stability of high chromium white cast iron(15.0wt.%) was investigated by means of optical microscopy(OM) and energy spectrum spectrometry(EDS).The results indicate that with increasing the concentration of carbon,the carbon of solid solution in the primary austenite increased, while the chromium was on the contrary, The increase of carbon content stabilized primary austenite under the condition that no secondary carbides precipitated, however, once secondary carbides precipitated, the stability of primary austenite deteriorated with the increase of carbon contents. 2.63wt.% C was the critical value of the secondary carbides precipitation in high chromium white cast iron(15.0wt.%).

High chromium cast iron and stainless steel bimetal were fabricated by liquid-solid composite casting .The interface diffusion behavior and microstructure evolution of high chromium cast iron were studied. The results indicated that interface element diffusion behavior between stainless steel and high chromium cast iron was obviously existed. Under experimental conditions, there were many refined grainy-shaped carbides precipitation in stainless steel near interface, located at austenite grain boundary and intragranular austenite. As for high chromium cast iron, the morphology of the carbides varied from the interface to the specimen edge. The rod shaped carbides approached to composite interface were finer and become coarser rod-like or blade-like with increased distance from the composite interface. The reasons for elements diffusion and microstructure change were associated with alloys contents and temperature field.

Erosion wear tests under different erosion slurry mediums were carried out to investigate erosion properties of the treated samples of ZM5 magnesium alloy by surface diffusion alloying processing (SDAP).The result indicated that the micro-hardness (HV172) near the surface of alloyed specimen was about twice more than that of its substrate(HV82) after treated at 390°C for 8h.The erosion wear resistance β (0.68×104 mm2/g) of the treated specimen was better than that of untreated specimen (0.48×104mm2/g) under the conditions of erosion slurry of oil and quartz. The difference of erosion wear resistance between them was primary due to cutting wear mechanism. While erosion mediums was changed to the slurry of water and quartz, the wear resistance β of the treated specimen increase up to 0.24×104 (mm2/g), and that of the untreated specimen was only 0.09×104 (mm2/g),the difference between them resulted from corrosion wear mechanism predominating, which worsen the erosion wear resistance β.