Use of salts of sulfonamidocarboxylic acids as corrosion inhibitors in aqueous systems

A method for preventing corrosion of metal in contact with a corrosive aqueous medium, wherein a compound of the formula I ##STR2## where R.sup.1 and R.sup.2 are phenyl which is unsubstituted or monosubstituted or disubstituted by alkyl of 1 to 6 carbon atoms, n is 0, 1 or 2 and m is 1 or 2, in the form of an alkali metal salt or an alkanolamine salt, is added to the corrosive aqueous medium as a corrosion inhibitor.