Corrosion inhibitors

Abstract

A composition and method for inhibiting corrosion of ferrous metals in contact with an aqueous solution comprising adding to the system from 0.1 to 500 ppm of an aminohydroxysuccinic acid compound selected from group consisting of compounds of the generalized formulas: ##STR1## wherein R is H or C.sub.1 to C.sub.6 alkyl, optionally substituted with --OH, --CO.sub.2 H, --SO.sub.3 H or phenyl, C.sub.4 C.sub.7 cycloalkyl, or phenyl which is optionally substituted with --OH, or --CO.sub.2 H, and R' is H, C.sub.1 to C.sub.6 alkyl, optionally substituted with --OH or CO.sub.2 H; and ##STR2## wherein R' is as above, and Z is selected from the group consisting of i) --(CH.sub.2).sub.n -- wherein n is an integer from 2 to 10, ii) --(CH.sub.2).sub.2 --X--(CH.sub.2).sub.2 -- wherein X is --O--, --S--, --NR'--; wherein R' is selected from the group consisting of H, C.sub.1 to C.sub.6 alkyl, hydroxyalkyl, carboxyallkyl, acyl, --C(O)OR'' wherein R'' is C.sub.1 C.sub.6 alkyl or benzyl and ##STR3## wherein R' is as above, ##STR4## wherein Y is H, C.sub.1 to C.sub.6 alkyl, alkoxy, halogen, --CO.sub.2 H, or --SO.sub.3 H, m is independently 0 or 1 and p is 1 or 2, and ##STR5## wherein R.sub.a and R.sub.b are independently H or C.sub.1 to C.sub.6 alkyl, Q is H or C.sub.1 to C.sub.6 alkyl and S is 0, 1 or 2; t is independently 0, 1, 2 or 3 and q is 0, 1, 2, or 3, and r is 1 or 2; or water soluble salts thereof.