Based on the study on behavior of nitriding and denitriding of stainless steel 304 in AOD refining process

the calculating models for nitriding and denitriding of steel in AOD process have been established. The verified results for the AOD nitriding model by 120 t AOD unit refining show that after picking out the error data

in oxidation third-period the percentage for absolute error of nitrogen content in steel less than 100 x 10

-4

% between measured and calculated values is up to 85% ； and for the AOD denitriding model

in reduction period and desulphurization period the percentage for that less than 100 x 10

-4

% between measured and calculated values is above 80%

and the aim ratio of nitrogen content in steel in AOD desulphurization period is about 90%.