<P> Dissimilar metals and alloys have different electrode potentials , and when two or more come into contact in an electrolyte , one metal acts as anode and the other as cathode . If the electrolyte contains only metal ions that are not easily reduced ( such as Na , Ca , K , Mg , or Zn ) , the cathode reaction is reduction of dissolved H to H or O to OH . The electropotential difference between the reactions at the two electrodes is the driving force for an accelerated attack on the anode metal , which dissolves into the electrolyte . This leads to the metal at the anode corroding more quickly than it otherwise would and corrosion at the cathode being inhibited . The presence of an electrolyte and an electrical conducting path between the metals is essential for galvanic corrosion to occur . The electrolyte provides a means for ion migration whereby ions move to prevent charge build - up that would otherwise stop the reaction . </P>
<P> Dissimilar metals and alloys have different electrode potentials , and when two or more come into contact in an electrolyte , one metal acts as anode and the other as cathode . If the electrolyte contains only metal ions that are not easily reduced ( such as Na , Ca , K , Mg , or Zn ) , the cathode reaction is reduction of dissolved H to H or O to OH . The electropotential difference between the reactions at the two electrodes is the driving force for an accelerated attack on the anode metal , which dissolves into the electrolyte . This leads to the metal at the anode corroding more quickly than it otherwise would and corrosion at the cathode being inhibited . The presence of an electrolyte and an electrical conducting path between the metals is essential for galvanic corrosion to occur . The electrolyte provides a means for ion migration whereby ions move to prevent charge build - up that would otherwise stop the reaction . </P>
where does corrosion occur in a galvanic cell
where does corrosion occur in a galvanic cell
at the anode
at the anode