Self-Study Program

10
Electrochemical potential series
Contact corrosion occurs when different
metals that lie far apart in the electrochemical
potential series come into contact under the
presence of an electrolyte.
The metal that is lower in the electrochemical
potential series is electrolysed.
The electrolysation is more pronounced the
further the metals are apart in the
electrochemical potential series.
Contact corrosion on aluminium leads to
rapid destruction at the contact point,
particularly of thin-walled components.
The material aluminium
Zn Cr Fe PbSn
NaCl
OH
2
+
Aluminium
Corrosion
SSP239_011
SSP239_052
Electrochemical potential series (extract)
Lead - Pb
Tin - Sn
Iron - Fe
Chromium - Cr
Zinc - Zn
Aluminium - Al