Evaluation of size distribution of small inclusions dispersed in molten steel by small angle diffraction high brilliant X ray

点击翻译按钮获取中文摘要

Ti oxides have a lot of different crystal structures, and their structures varies depend on Ti concentration in the Fe-Ti-O system. Furthermore, they form compounds and the solid solutions with the Fe oxide. Therefore, understanding of the precipitation behavior Ti oxides that have a various crystal structure (various lattice distance) can be very important to develop the oxide metallurgy technology. Thus, as first step, and thermodynamic evaluation of the deoxidation equilibrium of various Ti oxides have been carried out. (1) The phase identification of Ti oxide of about 1μm generated in melt Fe-Ti-O alloy was carried out by using EBSD. Based on the results, the range of the oxygen concentration of molten Fe-Ti-O system in equilibrated with various Ti oxides melt Fe-Ti-O alloy was accurately determined. (2) For molten Fe-Ti-O system, the nucleation starting temperature was measured by using DTA, measurement of the nucleation generation temperature of the Ti oxide from melt Fe-Ti-O alloy was carried out, and it has been found that the nucleation gstarting temperature vary based on Ti concentration in molten Fe-Ti-O system. Moreover, to establish the correlation between the 2-dimensional precipitation behavior and actual 3-dimensional behavior, CaCO_3 precipitation behavior from the solutions was observed by using the microscope. The correlation of precipitation behavior in two dimensions and three dimensions was evaluated based on the Fractal model. Along with carrying those experiments, it was found that the small angle analysis of precipitated particles in the molten steel by synchrotron radiation is rather difficult. Therefore, the nucleation behavior of CaCO_3 from the solution was analyzed by using conventional X-ray with small angle diffraction analysis, and was confirmed that the distribution evaluation was possible for the particles with up to the diameter of about 10μm.