Testing For Galvanic Corrosion: Risk Mitigation Explained

While galvanic corrosion is a serious threat and understanding why it occurs can make avoiding this typical corrosion type much simpler.

Corrosion is a vital concern when selecting piping materials and developing piping processes. While stainless steel is highly resistant to many forms of corrosion, being mindful of dangers is necessary to the safe, long-lasting operation and reducing expenses over the life of your system.

In this guide, we'll discuss galvanic corrosion, where and when it might happen, and how you can reduce the threat of or avoid galvanic corrosion when utilizing stainless steel pipe.


Also known as bimetallic corrosion or dissimilar metal corrosion, galvanic corrosion is when corrosion damage occurs due to two dissimilar metals coupling in the existence of an electrolyte.

So, breaking that down, it indicates three conditions must be satisfied for galvanic corrosion to end up being a concern:

Several metals need to be present with varying electrode capacities or nobility-- the greater the difference, the higher the danger of galvanic corrosion.

These metals should remain in electrical contact.

Exposure to an electrolyte-- such as saltwater-- needs to take place.

Simultaneously, one metal-- the anode-- will rust faster than it would alone, while the other-- the cathode-- will corrode slower than it would alone.


Much of decreasing galvanic corrosion threats is simply preventing mixes of the three elements listed above. However, for many markets-- such as those processing chemicals or running off-shore in salt-rich environments-- this is easier said than done.

Think about the following when developing or preserving piping processes where galvanic corrosion is an issue.

The Galvanic Series (Electrode Potential) Explained

Among the foundational steps to preventing galvanic corrosion is picking metals with similar electrode capacities or nobility.

As highlighted in the image above, lots of stainless-steel alloys rank toward the cathodic end of the scale. This indicates they are less likely to suffer damage from galvanic corrosion. However, if used with highly anodic fasteners, structural elements, valves, or other components, the big distinction in nobility can lead to fast degradation of the other elements.

This is frequently seen when carbon steel or aluminum is utilized together with stainless-steel piping.

Understanding Environmental Components of Galvanic Corrosion

It is important to note that galvanic corrosion dangers will likewise vary based on both metals' electrolytes. For instance, the threats of galvanic corrosion in extremely pure water are minimal. Yet, deploy the same metals in a marine or chloride-rich environment, and you could see corrosion happen very rapidly.

While your experience will depend on many aspects, and you should always seek advice from an engineer for precise information relating to your particular requirements, the following chart provides examples of galvanic corrosion dangers to expect from typical metal mixes.

Ways to Reduce Galvanic Corrosion Risk

Even with the perfect products selected, it might not be possible to remove galvanic corrosion threats. If so, insulating components and breaking the electrical path are effective options to boost corrosion resistance even more and ensure a long operational life.

Alternatives include:

Insulating dissimilar materials using non-conductive product coatings, greases, paints, treatments, or guides. Ideal protection is used by insulating both materials. Nevertheless, insulating simply the anodic product can assist slow galvanic corrosion progress even if it does not prevent it.

We utilize buffers-- such as pipe covers, clamp liners, and pads-- in between dissimilar metals to eliminate galvanic cell creation and disrupt electrical courses.

Plating, or galvanizing, is also an effective method of reducing galvanic corrosion risks or altering the electrode capacity of elements without totally changing their structure. For example, it is common to plate carbon steel fasteners with zinc to improve corrosion resistance greatly. However, any noble metal-- such as chrome, nickel, or gold-- can also be used.


While stainless-steel pipeline and piping parts are a popular choice due to their exceptional corrosion resistance, this very same resistance can also make matching other metals with stainless difficult when galvanic corrosion is worried.

Galvanic corrosion requires two dissimilar metals, in electrical contact, in the presence of an electrolyte to happen.

Metals even more apart on the Galvanic Scale (or with higher electrode capacity) are at greater risk of galvanic corrosion.

Environmental aspects (such as electrolyte concentrations, circulation rates, and temperatures) can further impact galvanic corrosion risks.

Insulation, buffers, and plating offer reliable methods to decrease corrosion threats when pairing other metals with stainless steel products.


  1. This comment has been removed by the author.

  2. In this post we read useful tips which is effective our thoughts. Understood easily that how it's work step by step Stainless Steel Hex Bolt Manufacturers If you wants more related services then must Jignesh Steel.

  3. After going through your contents I realize that this is the best of my knowledge as it provides the best information and suggestions. This is very helpful and share worthy. If you are looking for the best ASTM A193 B6 then visit VIHA STEEL & FORGING. Keep sharing more.