A ???noble??? metal is a metal with a low negative potential, which also means it is cathodic when compared to most other metals.Dissimilar metal corrosion is most severe when the potential difference between the two metals, or ???driving voltage,??? is the greatest.Fig(6-6) Galvanic Corrosion Cell Caused by Different MetalsExamples of active metals are new steel, aluminum, stainless steel (in the