Cathodic Protection Training Delivered in World-Class Facilities

Cathodic Protection Training Delivered in World-Class Facilities

The Who, How, Where, and When of CP Certification Courses

In this series of blogs discussing ICorr’s Cathodic Protection Certification Courses, we have examined:

  • Establishing competence in cathodic protection
  • Choosing which course is right for you
  • Charting your career with the CP certification scheme

In this last blog, we look at the who, how, where, and when of these groundbreaking courses.

A triumvirate of experience delivers exceptional CP training

We started updating our courses so that they would align perfectly with the new ISO 1527:2017. As is often the case, the planning and execution have taken a little longer than anticipated. We certainly were not helped by the interruption caused by the coronavirus pandemic.

What we had hoped to deliver in 2020 was delayed. It’s here now, though, and courses have got off to a flying start.

For this latest phase in delivery of exceptional training in all things corrosion, we have partnered with the Corrosion Prevention Association (CPA). If you don’t know who CPA are, here’s a brief rundown – the CPA:

  • Represents consultants, contractors, and engineers working in the field of corrosion prevention [primarily in the reinforced concrete industry]
  • Acts as the leading authority and source of information on cathodic protection and other corrosion prevention techniques
  • Shares the Institute of Corrosion’s values of encouraging a better understanding of corrosion and sharing of knowledge

CPA has extensive experience in the industry, including delivering seminars, demonstration days, holding industry events, providing CPD presentations, and, of course, online and in-person training programs.

To deliver the groundbreaking CP courses, the CPA partnered with Corrosion Control Services Limited (CCSL) to provide training facilities.

Best-in-class training facilities

CCSL has established an examination and test centre in Telford, Shropshire, and it really is a state-of-the-art facility. It is here that all our CP courses are delivered.

The Gary McKenzie Training and Examination Centre is an innovative development. We had no hesitation in approving it for courses in cathodic protection in reinforced concrete, and on-land (buried) and marine metallic structures.

Officially opened in May 2021, course delegates have already experienced all it has to offer. This includes ‘real-world’ testing grounds. Yes, course attendees will work on pipes and structures in settings that replicate being in the field. If it’s raining, be prepared to get wet!

When are our cathodic protection courses held?

The Level 1, Level 2, and Level 3 courses last between two and five days. If you are taking the exam, this is a separate one-day event with exam days tagged to the end of each course.

Course dates have been announced for through to September 2022, and there will be more to come. The courses are selling fast, and some are already fully booked. You can find out available dates for your chosen course here:

At the time of publication, depending upon the course, the course cost is £575 and £1,200, with exams costing between £330 and £375. Once you have completed the course and been successful in the exam, you will need to apply to the Institute of Corrosion for appropriate certification.

To book a course, please contact CPA on 01420 471614 or send an email to

For any further information, or to enquire about membership of the Institute of Corrosion, please contact us.



Charting Your Career with the Cathodic Protection Certification Scheme

Charting Your Career with the Cathodic Protection Certification Scheme

Certification to Support and Enhance Your CP Career

A career in cathodic protection can be developed with an employer or as a self-employed contractor. The work is interesting, often challenging, and well paid. As industry around the world seeks to combat the environmental, safety, and financial impact of corrosion, a career in this specialisation is supported by high demand for skilled operatives at all levels.

Specialising in cathodic protection offers a career path that could take you around the world, working for diverse companies in locations that stretch from pole to pole. As you climb the career ladder – possibly to establish your own company or, perhaps, as a senior lecturer in university – your career growth must be supported by additional qualifications and certification.

In fact, the structure of ICorr’s Certification Scheme for Cathodic Protection Personnel is designed to be an enabler of career progression in this specialisation. Effectively, your career advancement can be charted by each level of certification.

Starting out – Cathodic Protection Data Collector/Tester (Level 1)

As a starter in the industry, you don’t yet have any experience in cathodic protection.

The role of data collector or cathodic protection tester is likely to be combined with other duties. For example, as an electrical .

To be classed as competent for cathodic protection data collection and testing, you will need to be certified as a Level 1 Tester/Data Collector. This is the course intended for very new entrants to the CP industry. It’s also appropriate for staff who, on a part-time basis, collect and test as part of a wider job description.

Next step – Cathodic Protection Technician (Level 2)

As you gain experience, your role will expand. To take the next step, you will need to be certified as a Level 2 Technician. You will be responsible for testing and evaluation of cathodic protection systems and data. Your technical knowledge will include different CP systems, anode types, corrosion theory, reference electrodes, corrosion prevention, and an understanding of how CP works at a scientific level.

You might undertake work with specific instruction from senior staff with higher certification levels. You may also help prepare reports and make corrections to systems as approved by supervising staff.

This is a big step up from the duties of a data collector/tester, though you don’t need any specific experience in cathodic protection to take the course that certifies your competency to perform this role. However, before being certified as a Level 2 Technician [i.e. after the course and successful examination] you will require to have a minimum of one year of approved experience.

Supervisory roles – Senior Cathodic Protection Technician (Level 3)

At this stage of your career, you will now be expected to supervise lower-level staff in their cathodic protection work. Your knowledge bank will be substantial, and your duties may include:

  • Instructing work crews on the installation of cathodic protection systems, and maintenance.
  • Inspecting technician surveys and written documentation
  • Inspecting contractor procedures for corrosion compliance
  • Identifying problems and determining corrective action
  • Testing existing CP systems
  • Overseeing and instructing corrosion team members and CP technicians in corrosion-related requirements

You may also be required to provide feedback and training to other employees, and help to maintain safety standards. You could be responsible for reviewing, maintaining, and updating records, ensuring data integrity and adherence to controls, practices, and policies.

There are several ways in which you may be qualified to take the Level 3 Senior Technician Course and examination:

  • You should have at least six years’ experience (less, if suitably academically qualified)
  • You must hold Level 2 Cathodic Protection Technician Certification for the applicable sector in which you will be working


  • You should have at least one year’s experience and have attended the Level 2 training course to satisfy the educational and experience requirements to qualify for the Level 3 training course and examination.

Experienced senior roles – Cathodic Protection Specialist (Level 4)

Your career has led you to senior and management roles. At this level, you will be designing CP systems and providing technical expertise and guidance to others – such as those working in operations and engineering – to enable efficient and effective implementation, monitoring, and troubleshooting of cathodic protection assets.

Your experience is likely to include subjects and tasks such as:

  • Corrosion control regulations
  • Assessment and repair of pipeline defects
  • Technical support, training, and evaluation of corrosion technicians
  • Working knowledge of corrosion control databases and field data collection devices
  • Ability to consistently analyse and resolve corrosion control issues involving multiple components, personnel, and operations

Currently there is no course for this level of certification. You will, however, need to demonstrate your experience and expertise when applying for certification as a Level 4 Cathodic Protection Specialist as follows:

  • If progressing from Level 3, you will need three to eight years’ experience
  • If applying directly, you will need five to 12 years’ experience
  • Examination is required
  • You will need to supply evidence of work (including detailed complex design)
  • Validation by two referees is also required

The pinnacle of your career – Level 5 Cathodic Protection Expert

To achieve this level of certification, you must already be certified at level 4 in the same sector. You will have advanced the state of CP by scientific work, and have a broad understanding (at least) of all other sectors of CP.

It is likely that you will have published peer-reviewed papers, and have an established reputation in at least one sector within the industry.

This is not presently recognised/offered in the UK and many believe it to be an honorary title.  However, BS EN ISO 15257 states that there are activities that a Level 5 is competent to undertake that a Level 4 is not.

ICorr – Leading the way in CP career development through certification

A career in cathodic protection has much to offer. You’ll work on diverse projects, with the opportunity to work in all four corners of the globe. With a high demand for your skills and experience, you should never be short of rewarding opportunities to advance your career.

To maximise the benefits of a career in CP, you should gain certification as you progress. We have developed CP certification to an internationally recognised standard (ISO 1527:2017). Your certification validates that you have the minimum skills, knowledge, and experience to be certified as competent across all the disciplines within the CP field, including survey, design, installation, testing, maintenance, and the science of cathodic protection, at each successive rung of the career ladder.

At each level as detailed above, you must apply to the Institute of Corrosion for certification. Successfully completing the course and passing the exam is not enough on its own.

In our next article discussing cathodic protection courses, examination, and certification, we examine how the CP courses are delivered.

In the meantime, to learn more about our ground-breaking CP Certification Scheme and our comprehensive Cathodic Protection Certification Courses – and discuss which is right for you – email the Institute of Corrosion at



ISO 15257:2017 – Establishing Competence in Cathodic Protection

ISO 15257:2017 – Establishing Competence in Cathodic Protection

5 Levels of CP Certification

If you work in cathodic protection, you must be certified as competent to do so. This applies around the world, and the Institute of Corrosion (ICorr) has upgraded its courses to fully meet the requirements of the rewritten cathodic protection competence standard – BS EN ISO 15257:2017.

In this article, we introduce the standard and discuss who it applies to.

The aim of BS EN ISO 15257:2017

The standard defines five levels of competence for those working in cathodic protection (CP), and specifies a framework within which competence is established at each of these levels.

It specifies the minimum skills, knowledge, and experience a person must have to be certified as competent across each of the disciplines within the CP field, including survey, design, installation, testing, maintenance, and monitoring of CP.

The standard started as a British Standard and European Normative (BS EN) in 2006. “The rewritten ISO standard gives objective criteria and credentials that allow clients to know who is legitimate and who is selling snake oil,”, says Chris Wozencroft, Principal Engineer at Corrosion Engineering Solutions Ltd. and member of ICorr’s CP Governing Board (CPGB).

Do you need to be certified?

If you are a ‘cathodic protection person’, you should be certified as competent. The standard defines a cathodic protection person as someone ‘who devotes a regular and significant percentage of professional activity to the practical application of cathodic protection within one or more of the application sectors’.

Levels of competence

The standard sets out the five levels of competence with each step up in level including competence in the levels below. The competence levels are set out as follows:

Level 1: Cathodic Protection Data Collector (or Tester)

This certification allows you to collect CP performance data and perform other basic CP tasks requested of you by someone of Level 3 or higher. At this level, you won’t be responsible for analysing data, but you should have a good understanding of the measurements and causes of errors in them.

Level 2: Cathodic Protection Technician

When certified at Level 2, you shall be deemed competent to undertake a range of CP measurement, inspection, and supervisory activities that are delegated to you by persons at Level 3 or higher. However, you will not be responsible for determining the test method or technique to be used, or for the preparation of technical instructions and interpretation of results.

Level 3: Cathodic Protection Senior Technician

At Level 3, you will demonstrate that you have knowledge of the:

  • General principles of corrosion and CP
  • Principles of electricity
  • Significance of coatings and their influence on CP

You will also possess a detailed knowledge of CP test procedures and safety issues, and be able to prepare technical instructions for all lower-level CP persons, as well as assess all data collected from these tasks.

Level 4: Cathodic Protection Specialist

With a detailed knowledge of corrosion theory, principles of electricity, CP design, installation, commissioning, testing, and performance evaluation (including systems affected by interfering conditions), you could be certified at Level 4.

You can now design CP systems, define guidelines for monitoring them, and prepare technical instructions for all CP persons of lower levels.

Level 5: Cathodic Protection Expert

This is an honorary title for PhD qualified CP professionals, who have demonstrated all the competencies required in at lest one sector, together with a range of competencies in other sectors at the highest level, such as

  • Undertaking a range of high-level activities such as management of R&D projects
  • Publications in technical or scientific journals or books, lectures at congresses or training courses
  • Participation in standardisation or technical committees
  • Leading in the development of new technology or new applications
  • Editing scientific journals

Are you certified as competent in CP?

As you can see, ISO 12527:2017 provides a linear path of certification at specified levels of competence. This means that clients are better able to identify the person they need for specific projects and tasks, and you can prove your competency with your certification.

Under the previous standard, there were only three levels, which equate to Levels 2, 3, and 4 in the new standard.

The new scheme that has been developed based on ISO 15257:2017 has three elements:

  • Training
  • Examination
  • Certification

Certification is important because you need to prove you have experience before being certified as competent. With a discipline like CP, and a science that still holds so many uncertainties, it is unacceptable that someone should be able to leave college, take an exam, and be immediately deemed as competent.

You really do need a few years on the ground before you know what you’re doing in this game,” says Chris Wozencroft.

In our next article, we discuss the double-edged approach of certification in CP, and examine the application sectors to which the competence levels apply.

In the meantime, to learn more about the Certification Scheme for Cathodic Protection Personnel, email the Institute of Corrosion at

Introducing Cathodic Protection – 7 Cathodic Protection Myths Exploded

Introducing Cathodic Protection – 7 Cathodic Protection Myths Exploded

Breaking through to realities of cathodic protection

As we’ve described in our previous two articles an introduction to cathodic protection – discussing electrochemical corrosion and how cathodic protection works – cathodic protection is a highly effective method to prevent corrosion. It is used in multiple industries and environments, and without it the cost of corrosion on society, the economy and the environment would be far worse.

In this final article in the series, we dismantle seven common myths about cathodic protection.

Cathodic Protection Myth #1: Cathodic protection protects the whole structure, even if some of it is above the ground.

Reality – There is NO effect at all on the atmospheric corrosion of the piles, columns and beams above ground.

Cathodic Protection Myth #2: Cathodic protection on ONE side of a vessel (pipe/tank/lock gate) can protect both the inside and outside of the structure.

Reality – There is NO effect on corrosion on the other side of the vessel, unless there are holes that allow some cathodic protection current to flow in a common electrolyte from one side to the other.

Cathodic Protection Myth #3: If a buried pipeline is suffering from AC corrosion (AC induced from power transmission lines) it needs more CP to protect it.

Reality – NO! Don’t do it! NO! AC corrosion is complex, and an increased cathodic protection current density and more negative pipe/soil potentials will only enhance the risk of AC corrosion.

Cathodic Protection Myth #4: If I reverse the polarity of my impressed current cathodic protection system, I can pass more current. This must be better.

Reality – This has been done and proved to be incorrect. The structure supposedly being protected becomes the anode, and is consumed at around 10kg per amp per year. Entire sections of pipelines have been destroyed in this way.

Cathodic Protection Myth #5: You can reverse the current with a galvanic anode system.

Reality – In normal situations this is NOT possible. At elevated temperature there can be a reversal between zinc anodes and steel, but only if there are no chlorides present.

Cathodic Protection Myth #6: Galvanic anode CP systems are fit and forget.

Reality – If only this were true! All cathodic protection requires inspection and testing to determine if it is still functional and effective.

Cathodic Protection Myth #7: Galvanic anodes can only deliver a short design life.

Reality – It is normal for offshore structures to be well protected from immersed corrosion for more than 30 years by using aluminium alloy anodes. The early BP Forties platforms in the deep northern North Sea were protected for 40 years with a combination of coatings and large zinc anodes.

The challenges of using cathodic protection

Cathodic protection is used extensively to protect critical infrastructure from corrosion. Common uses include:

  • Oil and gas pipelines
  • Oil and gas storage facilities
  • Offshore oil, gas and renewable energy structures
  • Ships
  • Reinforced concrete in bridges and other structures

However, cathodic protection is a specialised area, requiring application of corrosion science, electrochemistry, electrical engineering, metallurgy, and, often, structural and mechanical engineering.

The standards (BS EN and BS EN ISOs), that cathodic protection professionals must work to, all make it clear that cathodic protection design must be undertaken by cathodic protection specialists who have a documented and appropriate level of competence.

BS EN ISO 15257 details the competencies that are required in all sectors of cathodic protection (buried, marine, steel-in-concrete, and internal). This standard also details the work that should be undertaken by cathodic protection Data Collectors or Testers, Technicians, Senior Technicians and Specialists or Engineers. Only personnel with appropriate levels of training, experience and competence can undertake work associated with cathodic protection:

  • Surveys
  • Designs
  • Installation
  • Testing
  • Commissioning
  • Performance assessment
  • Maintenance

In the UK, certification in accordance with ISO 15257 is increasingly required. 

Here’s one final myth that must be exploded:

Bonus Cathodic Protection Myth: There are graduate and postgraduate courses in cathodic protection engineering.

Reality – No, there aren’t! So how do you get the training and certification you need, either for your employees or as an independent cathodic protection specialist?

Breaking the catch 22 in cathodic protection training

It sounds like something of a catch 22, doesn’t it? You must be certified to work with cathodic protection engineering, but there are no specialist courses for graduates or postgraduates. Consequently, specialists may start with a degree in science or engineering – or perhaps an apprenticeship – and then take advantage of specialist training. The Institute of Corrosion offers both courses and certification in cathodic protection.

Our cathodic protection courses are perfect for companies that need their staff trained and certificated in cathodic protection, for independent specialists, and for managers who want a better understanding of what their employees and contractors in cathodic protection should be doing.

These courses provide all the training required (levels 1 to 3) by cathodic protection data collectors, technicians and senior technicians in the sectors of buried, marine, and steel-in-concrete cathodic protection.

In addition, we offer independent assessment of competence as defined in BS EN ISO 15257.

If you are a cathodic protection company or an independent cathodic protection specialist, training and certification from the Institute of Corrosion provides recognition of training, knowledge, skills, experience and expertise that is valid internationally. As the industry continues to become more regulated and standards-led, this recognition will enhance your reputation and work opportunities.

To learn more about our range of cathodic protection training courses and the experience and qualifications needed for certification, please visit our pages detailing the Cathodic Protection, Training, Assessment and Certification Scheme.

Introducing Cathodic Protection – How Does Cathodic Protection Work?

Introducing Cathodic Protection – How Does Cathodic Protection Work?

Cathodic protection methods – differences and similarities

In our last article, we examined electrochemical corrosion and introduced the major areas where cathodic protection is used to protect against corrosion in aggressive environments such as soils, waters, and chloride contaminated concrete.

In this article, we take a deeper dive into how cathodic protection works.

The two types of cathodic protection

There are two types of cathodic protection: galvanic anode and impressed current cathodic protection.

Both provide a cathodic protection current flow from cathodic protection anodes placed within the same electrolyte as the metal to be protected. The current flows from the anode into the electrolyte. It discharges onto the metal, controlling the corrosion. It must flow within the metallic circuit (the metal plus the cables) and back to the anode to complete the circuit.

Galvanic anode cathodic protection (GACP)

Galvanic anode cathodic protection works as summarised above.

The anode materials are alloys of either zinc, aluminium, or magnesium – all more active metals than, for example, carbon steel. These more active metals corrode preferentially to the steel when they are metallically connected to the steel in an electrolyte.

The corrosion current of the anode material is the cathodic protection current for the steel. The current flows through the electrolyte onto the steel, controlling its corrosion. The current returns to the anode in the metallic circuit.

You may have heard the term ‘sacrificial anodes’. However, though this terminology describes the anode materials and how they act (the galvanic anode corrodes preferentially to the steel), it was changed in Europe in the 1980s to ‘galvanic anodes’.

You may see galvanic anode cathodic protection identified by the acronym SACP or GACP.

·         How is galvanic anode cathodic protection used?

Offshore, anodes are normally cast onto structural tubular cores which are welded to the offshore structure during construction onshore.

Offshore oil and gas pipelines are protected with aluminium alloy or zinc bracelet anodes clamped over the protective coating and connected to the pipeline by short cables or welded connections. Such protection should last for 30 years or longer.

Onshore, short pipelines are often protected using magnesium anodes. These are cast onto steel cores and connected to the pipeline with cables. In soils of low electrical resistivity, extruded or continuously cast and hot-rolled zinc ribbon is used. Zinc ribbon is widely used as an earthing electrode to mitigate induced alternating current (AC) on buried pipelines.

Impressed current cathodic protection (ICCP)

Impressed current cathodic protection is provided by connecting a DC power source between the metal being protected and the cathodic protection anodes. In contrast to GACP, the cathodic protection current is supplied by the DC power source and not by corrosion of the anode itself.

The DC power supplies are typically transformer rectifiers (confusing acronyms include TR, TRU and T/R) which convert mains electricity to low voltage DC. In remote areas, solar panels and batteries are commonly used (and stolen); thermo-electric DC generators and both diesel and gas engines driving generators have also been used.

The negative pole is connected to the protected metal (‘negative drain point’), and the positive pole is connected to the anode. As with GACP, the cathodic protection current flows from the anode, through the electrolyte and onto the metal being protected.

The anodes can be scrap steel (a reasonably common practice in France, where old railway rails are often used in such applications), high silicon iron, or sophisticated ‘mixed metal oxides’ coated onto titanium. Other materials, including graphite, magnetite, lead, platinum-coated titanium and niobium, have also been used, though performance and cost have combined to reduce their use.

·         How is impressed current cathodic protection used?

Offshore, anodes are typically mixed metal oxide coated titanium (MMO/Ti). These can be used in both seawater and saline mud, though in the latter their consumption rate is greater.

For steel in concrete, most impressed current systems use MMO/Ti anodes either in mesh, strip, or tubular form. There is a tubular anode formed into a conductive ceramic of MMOs.

In onshore applications, groups of anodes are normally used in ‘groundbeds’, which may take the form of a long horizontal trench in which multiple anodes are buried in a carbonaceous backfill. This increases the surface area, reduces the electrical resistance to ground, and extends the anode life. Similarly, anodes and ‘coke’ can be used in deep boreholes or multiple shorter boreholes. Anodes are typically high silicon cast iron or MMO/Ti.

Most impressed current systems will require replacement after about 25 years.

Which form of cathodic protection is best?

If the cathodic protection system is well designed, installed, operated and maintained, both galvanic anode and impressed current cathodic protection can be equally effective. However, GACP is simpler and has proved to be more reliable offshore.

Onshore, ICCP systems are easier to access for maintenance and, once installed, their components are not subject to the challenges of offshore environments. If properly designed, ICCP can protect many kilometres of well-coated pipelines.

ICCP is also advantageous for bare or poorly coated steel as it can deliver hundreds of amps of low voltage direct current, while a typical galvanic anode will seldom deliver more than 5 amps.

Cathodic protection – a specialist operation

Cathodic protection is used extensively to protect critical infrastructure from corrosion. For example:

  • It is legally mandated for gas and oil pipelines to ensure their safe operation
  • Offshore gas and renewable energy structures are effectively mandated to receive effective cathodic protection by their certification bodies
  • Ships benefit from extended dry-docking rules if they have effective cathodic protection
  • The life of concrete bridges and structures affected by chlorides, from de-icing salts or marine exposure, is extended by cathodic protection
  • Newly constructed, reinforced concrete structures in severe exposure conditions also have extended life when cathodic protection is used

However, across all functions – from design through installation to testing and maintenance – cathodic protection is highly specialised. There are standards (BS ENs and BS EN ISOs) for cathodic protection applications for different structures in different environments.

A key takeaway from the standards is that they make it clear that cathodic design must be undertaken by cathodic specialists with a documented, appropriate level of competence.

How do you gain a cathodic protection specialisation?

There are no degrees that can be gained in cathodic protection, and there are no postgraduate courses in cathodic protection engineering, either. Instead, you find that cathodic protection specialists may hold a science or engineering degree (or complete an apprenticeship) before undertaking specific training and gaining experience and expertise in cathodic protection.

The Institute of Corrosion offers courses in cathodic protection, providing the training required for levels 1 to 3 for cathodic protection data collectors, technicians and senior technicians. These courses are produced, owned and administered by the Institute of Corrosion CP Governing Board (CPGB), part of the ICorr Professional Development and Training Committee (PDTC).

These courses are designed for those seeking the certification of competence in accordance with standard BS EN ISO 15257. We also find that these courses add value to managers and others who want to know what their cathodic protection staff and/or contractors must be doing and the limits of what they should do.

Independent of the cathodic protection courses and the PDTC and CPGB, the Institute of Corrosion also offers an independent assessment of competence through its Professional Assessment Committee (PAC). This is recognised internationally as confirmation of experience, knowledge and task skills as defined in standard BS EN ISO 15257; it is valid internationally.

For cathodic protection companies and for independent cathodic protection specialists, attainment of cathodic protection training and certification will ensure demonstration of competence, experience and expertise. This translates into more effective work, improving reputational excellence, and more employment opportunities.

To learn more about our range of cathodic protection training courses and the experience and qualifications needed for certification, please visit our pages detailing the Cathodic Protection, Training, Assessment and Certification Scheme.

In our next article, we explode 7 cathodic protection myths.

Introducing Cathodic Protection – Electrochemical Corrosion

Introducing Cathodic Protection – Electrochemical Corrosion

Corrosion and electrochemistry from Davy to today

Cathodic protection is a highly effective method of preventing corrosion, and is used in multiple industries and environments. Its history in corrosion science really begins when Sir Humphry Davy first discovered the cathodic protection principles and applied them to electrochemical corrosion.

Davy’s experiments led to a better understanding of electrochemical corrosion and the first use of cathodic protection in 1824, when Davy successfully protected a British Navy ship’s copper sheathing from corrosion in seawater by using iron anodes.

In this article, we examine the process of electrochemical corrosion as an introduction to cathodic protection.

What is electrochemical corrosion?

Electrochemical corrosion is a process in which current flows between the cathodic and anodic areas on metallic surfaces, resulting in corrosion. There are always multiple elements in this process:

  • A host metal or metals exposed in an electrolyte.
  • An electrolyte is a medium that can conduct electricity by movement of ions (for example, saltwater, soil, or the pore water in concrete)
  • A metallic path between the exposed metal surfaces. Examples of this include:
    • A buried steel pipeline, accidentally connected to a copper earthing system in a classical ‘galvanic couple’ (the steel being anodic to the copper)
    • A buried or immersed steel pipeline or structure on which ‘anodic’ and ‘cathodic’ areas naturally establish due to variance in either the steel composition/metallurgy or within the electrolyte

Corrosion initiates on the metal/electrolyte interface and, at these anodic areas, low voltage direct current (DC) flows off the anodic metal into the electrolyte. Charged ions are released into the electrolyte and electrons are released into the metal. By convention, DC flow is opposite to electron flow.

The simple electrochemical circuit is:

  • Within the electrolyte (that is in the soil, the sea or river water, or the pore water within concrete) DC flows OFF the corroding anodic areas.
  • This must complete the electrical circuit, so it flows in the electrolyte and discharges on the non-corroding cathodic areas. The DC flows in the metallic circuit electronically, by electron movement. In the electrolyte it is via ionic movement, termed ‘ionic conduction’. The cathodic areas, receiving current flow from the electrolyte, do not corrode.

The electrochemist, rather than the engineer, will describe precisely the same process as the anodic area losing ions to the electrolyte (metal loss) and electrons to the metal (electron flow); the process is the same, it just that by convention the directions of electron and ion flow are opposite to the DC current flow.

In electrochemical corrosion, the magnitude of current flow is directly proportional to the rate of corrosion: approximately 10kg of steel is consumed by 1 ampere DC passing off a steel surface for one year.

How does cathodic protection help prevent corrosion?

Depending on whether it is described by an electrochemist or an engineer, cathodic protection might be described as:

  • Replacing the lost electrons from an external source, thus changing an anodic area into a cathodic area and preventing corrosion (electrochemist)
  • Providing cathodic protection current to all areas of the metallic surface within the electrolyte, sufficient to make all surfaces cathodic (engineer)

Though different descriptions, these are the same process.

Where is cathodic protection used?

Cathodic protection is used around the world to protect against corrosion, especially in aggressive environments such as soils, waters, and chloride contaminated concrete. Applications include:

  • Buried and immersed storage tanks – external surfaces of bases of above ground storage tanks with corrosive foundations; inside crude oil storage tanks with highly saline ‘water bottoms’; inside storage tanks for seawater or raw water
  • Ships’ hulls’ externals and internally in seawater-filled ballast tanks and cooling water systems
  • Offshore oil rigs, platforms, and subsea completions
  • Offshore wind foundations and tidal generators
  • Pipelines – buried and immersed – both onshore and offshore
  • Well casings
  • Flood defences and lock gates
  • Reinforcement in concrete

Cathodic protection is a specialisation

Though used extensively, cathodic protection is highly specialised. To be successful it requires a combination of the application of corrosion science, electrochemistry, electrical engineering, metallurgy, and often structural and mechanical engineering.

There are effective Standards (BS ENs and BS EN ISOs) for a wide range of CP applications in different environments for different types of structures. They all have one thing in common: all make clear that CP design must be undertaken by CP specialists with a documented and appropriate level of competence.

The standards make it clear that all work associated with cathodic protection (such as design, installation, testing, commissioning, performance assessment, and maintenance) should be undertaken by personnel with appropriate training, experience and competence.

How do you become a cathodic protection specialist?

Despite the rigorous nature of the standards surrounding cathodic protection, there are no graduate or postgraduate courses in cathodic protection engineering.

Cathodic protection specialists may start with a science or engineering degree, or via apprenticeships and trade skills, then augment these with specific training, experience and expertise.

The Institute of Corrosion offers both courses and certification in cathodic protection.

·         Courses in cathodic protection

ICorr cathodic protection courses provide the training required for levels 1 to 3 for cathodic protection data collectors, technicians and senior technicians in the sectors of buried, marine, and steel-in-concrete cathodic protection.

While providing the knowledge and skills training detailed in standard BS EN ISO 15257, existing experience and task competency are required depending on the course level.

These courses are suitable for those seeking certification of competence in cathodic protection in accordance with ISO 15257, and also for managers and others who wish to have an introduction to cathodic protection so that they understand what their staff or contractors need to be able to do and the limits of what they should do, within the scope of the standards.

·         Certification in cathodic protection

Independently of the cathodic protection courses, we also operate an independent assessment of competence. The ICorr Professional Assessment Committee (PAC) assesses whether the applicant has the requisite levels of experience, training, knowledge, and task skills as defined in BS EN ISO 15257.

This certification is recognised and valid internationally. In the UK, almost all steel-in-concrete cathodic protection projects, including those for Highways England (previously the Highways Agency), require cathodic protection personnel to be certified in accordance with ISO 15257. In addition, National Grid and the distribution companies, and many marine, port, harbour and offshore operators, also require certification of cathodic protection personnel.

Sustainability in cathodic protection provision

Cathodic protection companies will experience increasing benefits from having their employees certified in line with BS EN ISO 15257. They will be better trained, more competent, and better aware of their responsibilities. Clients are increasingly purchasing services from companies whose staff are certified in cathodic protection. For independent contractors, certification will enhance your reputation, help you to work more effectively, and give greater access to employment opportunities.

To learn more about our range of cathodic protection training courses and the experience and qualifications needed for certification, please visit our pages detailing the Cathodic Protection, Training, Assessment and Certification Scheme.

In our next article, we take a closer look at how cathodic protection works.