Discover

Galvanic CORROSION

Overview of the physical phenomenon, material selection guide and MALTEP solutions

Physical Phenomena

Discover the physics behind the galvanic corrosion

Description of the galvanic corrosion phenomenon

Galvanic corrosion is the result of the following three conditions:

  • Metals of different nature
  • Contact between these metals
  • Presence of water, thus oxygen
The 3 factors for galvanic corrosion

To reduce galvanic corrosion it is therefore necessary eliminate one of the three conditions. The suppression of metals and water or oxygen present being impossible, it is recommended to avoid the direct contact between metals of different nature.

Galvanic corrosion induces an electrical current flowing between metals. This current generates a metalic ion exchange. The anode releases metalic ions, conversely, the cathode is charged with ions:

The steel dissolves (corrosion) bu depositing on copper (blackening) and in water. The difference of potential induced by the electric current is altering the less noble metal (the anode)

Material selection guide

Check the galvanic compatibility of materials

Choose compatible materials

Simply check the compatibility between the materials in contact. The columns and rows represent the two materials in contact:

  • Green: The combination is safe
  • Yellow: The combination presents a low risk
  • Red: The combination is not suitable
Couples galvaniques
Galvanic series
mV (millivolts)
Acier inoxydable 304L
Stainless steel 304L(1)
Cuivre
Copper(2)
Bronzes
Bronzes(2)
Laiton
Brass(2)
Acier inoxydable type 316
Stainless steel A4 type(2)
Etain
Tin(3)
Aciers
Steels(3)
Aluminium
Aluminium(3)
Acier galvanisé
Galvanized steel(3)
Zinc
Zinc(3)
Acier inoxydable 304L
Stainless steel 304L (1)
0 320 - - - 550 750 840 - 1150
Cuivre
Copper (2)
320 0 40 70 140 280 530 580 900 920
Bronzes
Bronzes (2)
- 40 0 30 100 240 490 540 860 880
Laitons
Brass (2)
- 70 30 0 70 210 460 510 830 850
Acier inoxydable type 316
Stainless steel A4 type (2)
- 140 100 70 0 140 390 440 760 780
Etain
Tin (3)
550 280 240 210 140 0 250 300 620 640
Aciers
Steels(3)
750 530 490 460 390 250 0 50 370 390
Aluminium
Aluminum (3)
840 580 540 510 440 300 50 0 320 340
Acier galvanisé
Galvanized steel (3)
- 900 860 830 760 620 370 320 0 20
Zinc
Zinc (3)
1150 920 880 850 780 640 390 340 20 0
  • (1) : High level of humidity
  • (2) : Low level of humidity
  • (3) : The metal is degraded

MALTEP Solutions

Discover MALTEP solutions

Simple and effective solutions

The range of MALTEP products includes a wide choice of materials, it is recommended to respect some simple rules in order to reduce the galvanic couple effect, to reduce the risk of corrosion and to ensure the sustainability of your equipments.

Respect as much as possible the homogeneity of the materials in contact

If the first solution is not possible, MALTEP offers different bimetallic products in copper and aluminium (lugs, plates and washers)

Discover some examples of products with bimetallic elements

close

Wishlist