| CPC C23C 22/361 (2013.01) [C23C 22/73 (2013.01); C23C 22/83 (2013.01); C23G 1/22 (2013.01); C23C 2222/10 (2013.01)] | 11 Claims |

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1. A system for treating a metal substrate comprising:
a conversion composition for application to a portion of a surface of the metal substrate, the conversion composition comprising a permanganate anion in an amount of 0.1 g/L to 1 g/L based on total weight of the conversion composition; and
a sealing composition for application to the portion of the surface of the metal substrate following application of the conversion composition, the sealing composition comprising a trivalent chromium cation in an amount of at least 0.01 g/L and no more than 1.0 g/L based on total weight of the sealing composition and a transition metal cation in addition to the trivalent chromium cation in an amount of 0.05 g/L to 5 g/L based on total weight of the sealing composition;
wherein the system excludes a treatment composition for application to the portion of the metal substrate following application of the conversion composition and prior to the sealing composition.
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