Research On Thermodynamic Model Of Deoxidation With Ba Alloys And It's Application In Steel-Making

The technology to produce clean steel is the basic to produce high capability and high quality products. The oxygen content in steel and the properties of deoxidizing inclusions affect the capabilities of steels directly. Therefore, one of the key problems to produce clean steel is how to deoxidize and control deoxidation products.The paper first compared with the common thermodynamic model, the Toop model in ternary metallic melts was established on the basis of the Miedema formation heat model .According to the Toop model and related thermodymic data, the Ba alloy melt thermodynamic property at 1600℃were calculated. Then the thermodynamic calculations of deoxidizing capabilities of Ba alloys were carried out respectively and the mechanism of controlling deoxidation products were systematically discussed. It found out the extent with liquid deoxidation products, the result indicated that control the Ba alloy to make the steel with lower total oxygen content.Based the thermodynamic calculation, the deoxidation experiments with Ba alloys were carried out on bearing steel. The aim of the experiments was to find out their deoxidation rules, and to study the relation between inclusions components and their property. The measures and ways of controlling inclusions components were also discussed.Compared with the traditional deoxidizers, the experimental results showed that when used Ba alloys as the deoxidizers in bearing steel, the total oxygen contents were lower and deoxidation products were well-distributed and the size and account of inclusions were lower, and the effect of AlSiBa was the best, which inclusion morphology were nearly global. In all the experiments including the inclusions containing Ba were not found, which illuminated the inclusions containing Ba floated out quickly, so they weren't found in liquid steel. Deoxidation with differ Ba content AlSiBa alloys were carried out in the experiment, which showed high Ba alloy not only made the melt oxygen fall rapidly, but also made the total oxygen content of steel fall into a stably level rapidly. By analyzing the deoxidation mechanism, it showed that Ba had better deoxidation capability and can improved the deoxidation capability of Si and Al in alloy. Ba also can increase the alloy density, adjust the inclusion melting point, and improve the fluidity of steel. So AlSiBa alloy with high Ba has better effect of deoxidation and controlling inclusion.