Investigation of the steelmaking process in converters with combined blowing

The process of the combined blowing is used for the processing of high-phosphorus cast-irons and is used in the West-European countries; mainly it being the LBE (Lance Bubbling Equilibrium)process with the oxygen blowing from above and neutral gases through the bottom. The technology usually involves two periods of blowing with the intermediate pouring out of slag and keeping the slag of the second period of blowing inside the converter. The table of the initial calculation data was presented by the results of the chemical analysis and the temperature of the metallic fusion of the 51-th melting, got in 300 t Krupp-Stahl converters and presented in periodic literature. The contents of carbon [C], manganese [Mn], sulphur [S], phosphorus [P], the activity of oxygen a[O], were used as independent variables and as an index of the oxidation of the metallic fusion and the temperature of the fusion (Т, С). Verification of accordance of variables values distribution to the law of normal distribution by means of Kolmogorov-Smirnov criterion shows, that in all the cases the significance level exceeds 5%, that is why the null-hypothesis that distribution conforms the normal law, can be accepted. The linear regression equation, which makes it possible to calculate the variable [C]values, shows that they are determined by the values of the variables [Р] and a[O]. The equation of regression coefficients, as well as the free member, become reliable at 5%-th level of reliability. The value of F-criterion of regression equation proves its adequacy The standard error in determining the values of the variable [C] exceeds the 5%-th level and is about 12%. Making evident the high dispersion of difference between the actual and forecast values of the dependent variable. The distribution graphic of the rest of the regressive model does not confirm the adequacy of the regressive equation. The availability of nonlinear trend of the regressive equation leads to the necessity of the transition from the linear model of regression equation to nonlinear one to provide a reliable foresight of the variable [C] values on the chemical composition of the fusion and its temperature