5 Ways to Avoid Galvanic Corrosion

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5 Ways to Avoid Galvanic Corrosion
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When two dissimilar metals come into contact with
each other in the presence of an electrolyte,
galvanic corrosion (also known as bimetallic
corrosion or dissimilar metal corrosion) occurs.
This form of corrosion is defined by the rapid
corrosion of one metal while the other is largely
untouched. To put it another way, one metal
becomes the anode and corrodes preferentially,
sacrificing itself to preserve the other metal,
the cathode.
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How to Prevent Galvanic Corrosion?

Galvanic corrosion is usually prevented by
removing the fundamental ingredients that allow
it to form. This usually entails blocking the
electrical channel in the system's metallic or
electrolyte components, eliminating oxygen from
the electrolyte, and adding corrosion inhibitors.
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1. Proper insulation

Placing a non-conductive material between the
contact points of the coupling metals is one of
the most effective techniques of breaking the
electrical channel in the electrochemical cell.
Galvanic corrosion happens when electrons travel
from the anode to the cathode, creating a
galvanic current in the system. The flow of
electrons is blocked by the insulation material,
which prevents oxidation and reduction reactions.
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2. Electrolyte Isolation

An electrolyte, which includes ions that assist
the oxidation and reduction reactions in the
galvanic cell, is one of the most important
ingredients required for galvanic corrosion to
occur. As a result, methods involving the
isolation of the interacting metals and the
electrolyte may be beneficial in preventing
galvanic corrosion. Water-repellent chemicals
operate as barriers between the metal substrate
and the electrolyte solution to achieve this.
Paints, coatings, oils, and greases have all been
utilised successfully in a variety of sectors.
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3. Choosing the Right Contacting Metals

By reducing the potential difference between the
metals, galvanic corrosion can be avoided. As
previously stated, the driving force is the
potential difference, which causes electrons to
flow from the anode to the cathode. The higher
the potential difference, the higher the induced
galvanic current and the faster the corrosion.
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4. Corrosion Inhibitors

Corrosion inhibitors are chemicals (typically
liquids) introduced to the electrolyte to stop
the chemical reactions that induce galvanic
corrosion. Inhibitors act in a variety of ways,
the majority of which involve complicated
chemical processes. However, inhibitors that
remove dissolved oxygen from the electrolyte
solution are the most effective against galvanic
corrosion. The possibility of reduction at the
anode is reduced when oxygen is removed. The
galvanic process is paused because cathodic
reactions are dependent on anodic reactions.
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5. Minimizing the Area Ratio

Several studies have found that the ratio of the
cathode to anode area influences the rate and
severity of galvanic corrosion. The greater the
rate of reduction at the anode, and hence the
more severe the consequent galvanic corrosion,
the larger the cathode area in respect to the
anode (i.e., the higher the cathode to anode
ratio). The smaller the cathode to anode area, on
the other hand, the less severe the degradation.
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Read More https//sites.google.com/view/vapor-co
rrosion-inhibitor/blog/5-ways-to-avoid-galvanic-co
rrosion?authuser2
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Select Your Galvanic Corrosion Option



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