Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Galvanic Corrosion vs. Electrode Potential

Introduction to electro chemical series and corrosion of metals.

Sponsored Links

The potential difference between an anode and a cathode can be measured by a voltage measuring device but since the absolute potential of an anode or cathode cannot be measured directly - all potential measurements are made against a standard electrode. The standard electrode potential is set to zero and the measured potential difference can be considered as absolute.

Standard Hydrogen Electrode

  • The half-cell in which the hydrogen reaction takes place is called the Standard Hydrogen Electrode - SHE

Standard Electrode Potential

  • The potential difference measured between a metal M and the Standard Hydrogen Electrode - SHE

The electro-chemical series (electro-motive series) is a list of metals arranged in order of their standard potentials to the hydrogen electrode:

Elements - Electrode Potential
ElementElectrode Potential
(volts)
Lithium -3.04
Rubidium -2.92
Potassium -2.92
Calcium -2.87
Barium -2.80
Sodium -2.71
Magnesium -2.37
Beryllium -1.85
Aluminum -1.67
Manganese -1.19
Zinc -0.76
Chromium -0.74
Tungsten -0.58
Iron -0.44
Cadmium -0.40
Cobalt -0.28
Nickel -0.24
Tin -0.14
Lead -0.13
Hydrogen +0.00
Antimony +0.10
Copper +0.34
Iodine +0.54
Silver +0.80
Mercury +0.85
Bromine +1.07
Platinum +1.20
Chlorine +1.36
Gold +1.50
Fluorine +2.87

Note! - metals higher up in the electro-chemical series displaces metals lower in the series - which means that when connecting two metals with different potentials the metal with the lowest potential corrodes.

Elements - Standard Electrode Potential vs. Hydrogen Electrode

Corrosion Problem when Connecting Copper and Iron/Steel

A very common connection in piping systems are copper and iron/steel. with this connection iron/steel corrodes many times faster than iron/steel alone.

Sponsored Links

Related Topics

  • Corrosion

    Corrosion in piping systems caused by thermodynamic and electrochemical processes - corrosion problems and methods of protection and prevention.
  • Electrical

    Electrical units, amps and electrical wiring, wire gauge and AWG, electrical formulas and motors.
  • Miscellaneous

    Engineering related topics like Beaufort Wind Scale, CE-marking, drawing standards and more.

Related Documents

Sponsored Links

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

Citation

This page can be cited as

  • The Engineering ToolBox (2003). Galvanic Corrosion vs. Electrode Potential. [online] Available at: https://www.engineeringtoolbox.com/electrode-potential-d_482.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































2.19.10

Sponsored Links
.