Corrosion inhibiting compositions including bis-imidazoline compounds derived from enriched linear tetramines

A method of inhibiting corrosion of a substrate comprising a ferrous metal, the method comprising a step of contacting the ferrous metal with composition comprising a bis-imidazoline compound and at least one nonionic surfactant, and wherein the bis-imidazoline compound has the following structure:

• wherein:
• each Z1, Z2, Z3, Z4, Z5, and Z6 independently is H;
• a hydrocarbyl of 1 to 10 carbon atoms;
• and/or at least first and second of the Z1, Z2, Z3, Z4, Z5, and Z6 moieties are linked to each other in a manner effective to form a divalent moiety that attaches to the corresponding imidazoline ring(s) at two attachment sites;
• and
• each RH independently is a hydrophobic, aliphatic, monovalent moiety comprising 6 to 50 carbon atoms.