| abstract |
Disclosed are pretreatment compositions and associated methods for treating metal substrates with pretreatment compositions, including ferrous substrates, such as cold rolled steel and electrogalvanized steel. The pretreatment composition includes: (a) a group IIIB and/or IVB metal; (b) free fluorine; (c) a source of aluminum ions; and (d) water. The methods include contacting the metal substrates with the pretreatment composition. |