High Chromium Cast Iron Solidification Path And Carbide Precipitation Forecast

The high chromium cast iron has been widely used in mining, building materials, metallurgy, thermal power and other industries, and it is recognized as a good anti-wear material at home and abroad. Carbides in high chromium cast iron play an important role in the excellent wear resistance of high chromium cast iron. Alloying is one of the most commonly way to improve the microstructure and properties of high chromium cast iron, adding small amounts of alloying elements in cast iron, improving the matrix structure, improving the morphology of the carbides and then improving the performance of cast iron. Therefore, research on the effects of alloying on the high chromium cast iron solidification process is necessary.Compared to hypoeutectic high chromium cast iron, the carbon content and chromium content of hypereutectic high chromium cast iron is much higher. The carbides number increased considerably and the hardness of the material also has improved considerably, so this research is to design a reasonable hypereutectic high chromium cast iron components. And by adding certain content of titanium, titanium and carbon react with TiC particles at high temperatures. So the titanium element in the cast iron in the form of titanium carbide uniformly distributed in the liquid hot metal to be crystalline in order to play the role of exotic nuclei, to refine the austenite grain size and control eutectic carbides grew up role.In this study,use thermocouples and data acquisition system to measure the casting cooling rate; use WinROOF software for determination of the volume fraction of carbides; use X-Pert Pro MPD ray diffraction for phase analysis.In this study, use the FORTRAN programming language to write the calculation procedure.According to the solidification of hypereutectic high chromium cast iron by adding titanium element measured temperature drop curve, to adjust the convection heat transfer coefficient by using two-dimensional heat conduction equation, get the grid points enthalpy, and use the law of microsegregation of multicomponent alloys at the same time(In this paper, use partial equilibrium model and lever rule model), then get the solution of overall temperature distribution, volume fraction and composition of precipitates.According to the simulation results, analyze the temperature differences in different locations within the ingot solidification path and compare it with three different alloy microsegregation models (lever rule, Guliver-Scheil model and partial equilibrium model); According to simulated precipitation phase volume fraction and composition, analyze the number and concentration of carbide precipitation, and compared with experimental results.