[en] A method of thermodynamic analysis of intergranular corrosion of austenitic steels was used for finding an analytical dependence of a corrosion index - the maximum temperature (Tsub(max)) of intergranular corrosion, on the chemical composition of the steel. A lower carbon (nitrogen) activity leads to a lower Tsub(max), i.e. to a higher resistance of steel to this type of corrosion. It is shown analytically that Tsub(max)<=Tsub(eq), an equilibrium temperature of carbide formation in steel, and also the difference 1/Tsub(eq) - 1/T are governed primarily by the concentration of chromium in the steel. Agreement of the dependencies obtained with the available experimental data points to the possibility of using the proposed method of finding Tsub(max) on the basis of thermodynamic data