3.1.3.1 Corrosion Reactions Geometry

Corrosion reactions happen in one anodic reaction (losing an electron) and – based on several factors such as, but not limited to, oxygen availability, pH, electrochemical stability of chemicals in the environment, temperature, and the like – several cathodic reactions (gaining electrons) that if one is not happening, the other one can replace it. Therefore, right from the beginning, the electrochemistry of corrosion is based on not one but more than one reaction.

In addition to that, real‐life working conditions are far different from controlled, design conditions of corrosion laboratories; under laboratory conditions corrosion reactions are mimicked, accelerated, or reconstructed. These three features which are essential to laboratory experiments, do show the deep gap between experimental and industrially experienced findings.

Under working circumstances, mostly several corrosion reactions are operative. Some examples could be:

1. Hydrotested pipelines; in these systems there are at least four corrosion processes that, based on the chemistry and microbiological as well as electrochemical conditions, could exist [18], the most important of which being microbiologically influenced corrosion (MIC). In a system as such, it is very important to know if the involved governing corrosion processes are acting in series or in parallel geometry to each other: if the MIC problem can initiate or launch galvanic corrosion between the weld and the parent material of the pipe, then by solving either end of the problem (treating MIC or resolving the existing corrosion potential between the weld and the parent material), the corrosion problem can be solved.
2. Bioleaching tanks; in these tanks the normal process for tank bioleaching is that bacterial culture containing Sulfur oxidizing bacteria (SOB) will dissolve certain mineral (for example copper) concentrates to yield an industrially pure metallic form of the required element. Due to the very nature of the reactions in the tank, both erosion (as induced by concentrate lumps accelerating by the action of a mixer) and MIC, as induced by the action of the bacteria, can exist. It is then a matter of the electrochemistry, as well as the hydrodynamic of the concentrates inside the tank, that being in series or parallel geometry is determined.

Having a series or parallel corrosion reactions geometry has a very important impact on the way an overall corrosion problem is being treated; consulting efforts for a series corrosion geometry could be much easier and even more cost‐effective than a parallel geometry, by picking up the main corrosion process and treating it, it is highly likely that the overall corrosion problem will be resolved. In case of a parallel geometry, however, such chances are very slim, as it is highly likely that the involved corrosion reactions are acting independently from each other so that by solving one, the others will not be resolved. In addition, it is also possible that one branch of an overall parallel corrosion geometry will itself consist of a series of parallel and series geometries, thus making the overall picture even more complicated. Figure 3.7 shows an example of such a complex system in which external corrosion of a buried pipeline has been illustrated. In this respect, overall corrosion geometry is in parallel geometry consisting of three rows. Each row consists of corrosion geometries which are in series form.

For instance, the first row discusses soil properties from soil particle size (I) to its microbiology (II), and its pH, moisture, and conductivity (III). Likewise, the other rows will be related to other components of the whole corrosion scheme.

The complexity observed in the two examples given above can also be seen in other equipment and assets. As can also be seen, it is not that easy to talk about all possible corrosion scenarios if the geometry of such reactions with regard to each other is not known. A skillful corrosion engineer may realize what the corrosion processes are in each asset, but it is equally important to realize how these corrosion processes are prevailing in the overall corrosion scheme in the first place.

3.1.3.2 Failure

Failure is normally regarded as a phenomenon where the extent of physical damage is so large that the equipment cannot be used any longer. Failure seems to have been understood as a self‐evident issue so that by merely speaking about it, everyone would know what the topic is, but the fact is that it is not that straight forward to define failure.

In order to define failure, we must remind ourselves again about a principle that we mentioned earlier; our philosophy must not be treatment of failure but finding ways to avoid allowing failure to occur. In other words, our mission must be to prevent ways by which failure is highly likely to happen, not the failure per se. In this regard, our job will be more or less like crisis management; crisis by definition has no management as it is unmanageable. It is in fact pre‐ and post‐crisis conditions that can be managed. Pre‐crisis conditions must be managed effectively not to give way to crisis, and post‐crisis conditions must be managed to minimize the impact of crisis.

The thermodynamics of corrosion was emphasized to show that it is indeed a naturally occurring process. This means that corrosion cannot be stopped (the next section will discuss CP and CC and what the differences are between them). It can alternatively be said that corrosion is something that one has to accept, as long as pitting that would occur as a result of non‐uniform, localized corrosion is not leading to leakage. Prior to that, we want uniform corrosion (that is easier to handle in both prediction of its effects and controlling them) not to be replaced by non‐uniform, localized corrosion, an important result of which is pitting. While there have been many attempts to find an algorithm/pattern to predict pitting (even by using scholastic approaches), the unpredictable nature of pitting has always remained like a Damocles sword upon the head of corrosion technologists and engineers. Therefore, what is desired for us as operators or maintenance specialists with regards to CM can be summarized as in Figure 3.8 as an example of what we can call a 'corrosion safety procedure' for an asset such as a pipeline:

Taking the metaphor of a train reaching its last station, as far as corrosion safety procedure is concerned, leakage is the last station for the safety train. After the last stop, seen here as 'leakage' from the pipe, failure is inevitable. Therefore, failure in its classic meaning is where the mechanical integrity of the asset is lost and something like leakage from a pipe occurs. In pure engineering terms, failure is where the asset becomes useless.

The lack of usefulness and loss of mechanical integrity and strength has been introduced into corrosion engineers' books and nomenclature from a mechanical engineering understanding of materials.

For us, the stages through which failure is facilitated are important. In fact, it is only through these stages that a corrosion engineer can have the chance of controlling corrosion (in the next section we will explain the vast differences between CC and CP). To explain these stages, we need to become familiar with three definitions that we will be using through this chapter:

• Fit‐For‐Service State (FFS): When an asset/equipment passes all the necessary tests as required by standards and professional approval of an inspector, it is said that the asset is ready to be put into service and it is fit for the intended service. In this state, it can safely be assumed that the asset is corrosion‐free, or at least the extent/severity of corrosion is not significant enough to prevent the asset from being labeled as FFS.
• Pseudo‐FFS State: As soon as the equipment is put into service, it will face conditions that will affect its corrosion resistance. In other words, the asset will experience corrosion immediately after being put into service. When the asset undergoes this status, it is still being used by the operator of the plant or asset manager simply because the measured corrosion rates are still within acceptable range or the corrosion is still within the limits of being controllable. This state is not the same as FFS state but is similar to it, thus the name pseudo‐FFS.
• Zugzwang State: Zugzwang is a term in chess, simply meaning that whatever move one does, one will lose. No matter what your position is in the game, the game is doomed. In this context, we define Zugzwang state as per the below two definitions, and based on whichever would fit the situation of the asset, we may call it a Zugzwang effect status, Figure 3.9.

Figure 3.10 shows two examples of pseudo‐FFS and Zugzwang effect state.

In Figure 3.10, figure A shows an example of an asset in its Zugzwang effect state, whereas figure B shows an asset in its pseudo‐FFS state. In figure (A), the pipe is out of service completely due to the existence of the through‐wall hole. However, in figure (B) the asset is still in use merely because its condition is not critical enough to push it out of service. In fact, a great number of assets already in use in all industries are in their pseudo‐FFS status.

Based on the above, then, failure will be put into a new context which is simply this: Failure is when an asset reaches its Zugzwang effect state. Alternatively, the job of a corrosion consultant/engineer must be two‐fold; increasing the time between FFS and pseudo‐FFS states as well as the time between pseudo‐FFS and Zugzwang effect states. The relationship between these status conditions through which the asset will travel is schematically shown in Figure 3.11.

As components in Figure 3.11 show, as the asset moves from FFS toward pseudo‐FFS, and from pseudo‐FFS to Zugzwang effect status, there is a need for both inspection and maintenance. As implied earlier, the shorter the distance between pseudo‐FFS and Zugzwang effect status points, the more likely that failure will happen. The farther the distance between FFS and pseudo‐FFS, the safer the asset is to operate. This is also applicable should the distance between pseudo‐FFS and Zugzwang effect state be as far as possible, because that would mean that the equipment is in such good shape that failure is not likely to happen within a short time.

Therefore, by using the above concepts it is now possible to define what any useful CM must aim for. This can be stated as below diagram, Figure 3.12.

As Figure 3.12 shows, there are milestones that can be assigned to the service life of an asset from the time it passes all the required inspection and fit‐for service standards and codes, to the time it arrives at its Zugzwang effect state and it has failed. This pathway will also involve both inspectors and corrosion engineers/consultants, as well as integrity management technologists.

While the figure is self‐descriptive, particularly regarding what was mentioned above, it is worth noticing that the expertise involved and highlighted in Figure 3.12 are not all that is required. In other words, there is certainly a blend of experts and expertise needed to gain a correct evaluation and assessment. This is particularly true when Figure 3.12 is looked at within the context of Figure 3.11. As it appears from Figure 3.11, inspection and maintenance experts are to accompany the CM consultant at all times. It is also obvious that to keep the asset at its FFS state for as long as possible, technical feedback from inspectors is vital; it is based on what they see and report that the CM engineer can decide how critical the situation is and how it must be handled.

It is also a very important to understand that any CM approach is a collective work and it flows from bottom to top, and not the other way. What is meant here is that top management will be provided the feedback from the CM team, and if the decision taken by the top management proves to be incorrect down the line, it is highly possible that the CM team have not communicated effectively enough with management. We have seen an example of such poor communication between the engineering team and the financial management so that just based on pure accounting (not economical) considerations, refusal to use a better inhibitor instead of a less effective but less expensive corrosion inhibitor cost the plant dearly [5].

No CM scheme would be complete without discussing the important difference between CP and CC. This is a concept that, even by corrosion professionals, is often neglected and used without paying attention within a CM scheme; if the differences between these two terminologies are not taken into consideration, several confusions may be created. We will explain these terms in the next section.

3.1.3.3 Corrosion Prevention and Corrosion Control

Thermodynamics of corrosion teaches us that corrosion cannot be stopped, nor can it be prevented. However, CP and CC are terms that are being used interchangeably even in many official documents related to CM; as reported by NACE [15], one of the objectives mentioned in the long‐term corrosion strategy plan submitted by the US Department of Defense to the Congress in 2003, reads verbatim "Formation of a multi‐service corrosion prevention and control … team."

The fact, however, is that CP and CC are not the same at all. CP and CC differ from each other in features that can be summarized as in Table 3.2:

When we are in CP mode, based on the nomenclature we developed in the previous section, all efforts must be done to stay at FFS without letting the asset to move toward the pseudo‐FFS state. When on CC, all efforts must be performed so as not to arrive at Zugzwang effect state. This is a very important matter, as by knowing where the asset is the required strategy will be prepared, and for that reason it will be possible to prepare the required strategy.

Distinguishing CP as described in Table 3.2 also reveals and explains the seemingly contradicting issues between thermodynamics of corrosion (that defies prevention of corrosion) and the way corrosion technologists normally refer to CP. As it appears, even when we are in CC mode, corrosion is not being prevented but it is kept within restrains to keep it manageable enough. On the other hand, CP in this context can only be mentioned if right from the beginning all possible conditions leading to corrosion are seen and addressed.

An example of CP could be by changing the design. An example for a design change that would eliminate the corrosion problem (appearing in the form of corrosion under deposition due to the establishment of differential aeration cells) is to solve a galvanic corrosion problem of a carbon steel pipe with a small total area, with respect to a stainless steel pipe with a larger area (small cathode versus a large cathode that will be leading into sever corrosion), by either using the same material as the stainless steel pipe or using stainless steel as the anode and the carbon steel pipe as the cathode (small cathode versus large anode). Yet another example could be putting a valve under a suitable place in a basin so that by discharging the fluid, no stagnant conditions for the fluid inside the basin will be created, leading to possible corrosion mechanisms under the deposit (such as but not limited to, MIC).

From another point of view, CC is dealing with 'as is' whereas CP is dealing with 'to be' conditions of the asset. As is, as the name implies, shows the present condition of the asset. In other words, it shows how tolerable corrosion conditions are when the asset is considered from a CM point of view. Taking CP as an ideal state of engineering CM measures, to be shows the ultimate solution or conditions that can be expected. It follows that if the current (as is) condition of flow rate in a pipeline is, for example, less than 1.5 m/s so that stagnant conditions are encouraged leading possibly into the likelihood for MIC to develop, the target (to be) must be increasing the flow rate to disturb conditions for biofilm formation.² When the flow rate is below the limit mentioned, the conditions will need to be controlled (CC), and when we increase the flow rate so that biofilm formation is prevented (²), it is then as if biofilm formation as a prerequisite for MIC has been prevented (CP).

3.1.3.4 CM Model

The corrosion model we are presenting here rests on more than two decades of personal experience in CM and troubleshooting in various industries around the globe. In the above sentence we have emphasized upon there important elements that serve to qualify us for presenting a model:

• Field as well as academic experience; CM models must not be developed based on either pure field or academic skills and must actually look into combining the two within a suitable context. While the framework and context of such a blend must rely on theoretical basis, the application must be sensible enough when applied,
• Different industries; so far all the CM models we have observed and to the best of our knowledge, have been proposed to deal with oil and gas industry, perhaps with the exception of one model suggested to deal with CM issues in mining industry in Western Australia [19]. The fact is that corrosion is not just an issue in oil and gas industry, but in all industries ranging from mining to power generation and others, therefore, the more diverse industries one has knowledge of, the better the engineering understanding of the systems and processes. In addition, in some industries it is the process‐associated corrosion problems that are of interest. In fact, corrosion problems in any industry can be divided into three categories; (1) corrosion problems associated with the main process, (2) corrosion problems associated with auxiliary systems, and (3) corrosion problems associated with safety systems and equipment. In a power plant, for instance, category 1 problems are associated with corrosion problems for boiler, turbine, and condenser; whereas category 2 problems are those related to cooling tower, soot blowers, or boiler feed pump; and category 3 corrosion problems are mainly associated with underground metallic firewater rings. In a petrochemical plant, for example, category 1 and category 2 corrosion problems are of significance and most of the time category 3 problems are not taken seriously unless there has been a history related to it. Working as a corrosion consultant for a wide range of industries gives one the opportunity of getting familiar with the work culture of each, and therefore allows a much broader horizon for engineering disciplines than having worked in just one business in a given industry,
• Having a rather global culture about corrosion is a vital feature of any CM model that is to be proposed on an international level; the main defect of models proposed by mostly Western‐minded professionals is that they look at CM through their own window. For an industry that exists in a country where the currency rate between internationally accepted monetary units such as dollars or euro versus its national monetary system is not stable, it is quite unrealistic to propose expensive means of corrosion monitoring, inspection, and treatment. In a culture where there is no previous history about cost of corrosion or even a record about parameters required to define a corrosion cost model (to be discussed in the next section), not giving an algorithm on how to obtain such data, any CM model is to be doomed with incompetency when faced with realities.

While the Javaherdashti CM model takes the essential elements of CM that, like any other CM model is more or less similar for all CM models, its successful application is only possible if all the six elements for a system of management of corrosion are also ready and applicable.

The Javaherdashti CM model has four phases and six steps, as we will now discuss.

3.1.7.1 Corrosion Cost Estimation Model

Thus far, we talked about technicalities that must be involved in any corrosion related matter for which a CM model is either to be developed or applied. However no CM model will be completed if there is no clear approach for considering the economy of the damage imposed by corrosion.

The importance of having a corrosion cost model in place is that it can largely serve to justify the costs associated with dealing with corrosion. These costs range from those are related to exploring corrosion and root cause analysis to finding the best treatment method. In all these scenarios, it is essential for the business owner to justify why these expenses are necessary.

While some economical aspects of corrosion will be discussed later in this book, it is essential to have an idea about what is currently available as the toolbox necessary for researchers and investigators, particularly concerning estimating the cost of corrosion. Details of such models have been given in part in several publications [15,21–27].

Research about the cost of corrosion dates back more than 70 years; the cost must be expressed based on a measure that is a common denominator of all economic parameters in a country. It is obviously not reasonable to base the cost estimation model upon variable parameters that are not the same for developed and developing countries. However, the common outcome is that the cost of corrosion is expressed as a percentage of GDP (gross domestic product) or GNP (gross national product) of a given country. The cost of corrosion can be expressed regardless of the differences existing among countries; for example, if in country A the cost of corrosion is 3% of its GDP and in country B the cost of corrosion is 5% of its GDP, it does not mean that A and B have the same GDP, it simply shows how much of their wealth is being consumed by corrosion.

There are basically four models for estimation economic cost of corrosion as follows:

1. Uhlig Model, named after Dr. H.·H. Ublig, this model has features such as:
   1. It is rather a conservative model that gives minimum values for corrosion costs.
   2. Its basic assumption is that direct and indirect costs of corrosion are equal.
   3. Initial data to construct the model are taken from producers and not consumers.
   4. This model cannot express the corrosion cost distribution scheme within a given industry, nor can it calculate how much a certain industry can save on CM.
   5. This model does not present any particular method to calculate indirect costs of corrosion.
   6. Data collection is carried out by submitting questionnairs.
   7. This model has been used to calculate the cost of corrosion in the USA, India, Japan, and China.
2. The Hoar Method, named after efforts organized and conducted by Dr. T. P. Hoar has the following features:
   1. In this model, input and feedback on corrosion costs are inquired from both industry experts and academics.
   2. Hoar model is industry‐based.
   3. Direct cost of corrosion as calculated by Hoar model is always higher than that calculated by Uhlig model.
   4. No clear methodology to calculate indirect cost of corrosion.
   5. Data collection is carried out by submitting questionnairs.
   6. This model has been used in the UK, Japan, and China.

      

3. Input/Output model, also known as I/O model can be schematically shown as in Figure 3.14.

   Some features of I/O model are as below:

   1. There are uncertainties about both the capital cost and intermediate outputs.
   2. For each industry sector, the tedious job of calculation of cost coefficients (the coefficients that show how different sectors are mathematically interrelated) is required.
   3. Despite the complexity of this model and difficulties associated with it, it is claimed that for a country like India, feeding the inputs for four decades into such a model has yielded a simple equation that can calculate the cost of corrosion in this country for each year required.
   4. There is no particular methodology to calculate indirect corrosion costs other than inter‐sectors costs.
   5. This model has been used in the USA, Australia, India, Japan, and Turkey.
4. LCC analysis, has the following main features:
   1. Compared to the previous three models, this model appears as more realistic.
   2. LCC model is applicable to calculate cost of corrosion in equipment, structures, and factories.
   3. Applying this model to India has always demonstrated cost coefficients lower than those obtained by applying I/O model.
   4. This model is not suitable for considering all factors and parameters involved in indirect costs of corrosion due to the ever‐changing, dynamic nature of interactions among variables related to the indirect cost of corrosion.

All the models discussed above have their pros and cons and it would obviously be a more thorough approach if at least two of them are used together for one corrosion case and the results compared. In addition, it must be noted that these four models discussed earlier do lack a clear methodology to quantify the indirect costs of corrosion. This is a very significant aspect of these models that must be taken into consideration when these models are to be employed for any management of corrosion approach.

3.1.7.2 Corrosion Knowledge Management (CKM)

An integral part of a management of corrosion program is to have a plan ready to allow us to measure, either via quantity or quality, the impact of management parameters on the way corrosion is being treated.

We introduced CKM over two decades ago. CKM is a managerial tool specially design to advise managers with little or no technical knowledge of corrosion about how to deal with corrosion as an issue in both the present [28–31] and future [32] states of their industry.

While CM deals with the risk of corrosion, CKM deals with the management side of it, which also includes the economical/ecological impacts of corrosion. We have explained the similarities and differences between CM and CKM elsewhere [33].

The main algorithm to be followed regarding a CKM‐based approach is as per the steps below:

• Step 1: As per the industry and the plant to be investigated, at least two of the four internationally acceptable corrosion cost models are selected and applied;
• Step 2: The outcomes of the models are compared, and the range of corrosion costs is determined;
• Step 3: The findings are reported to the business owner/high ranking manager;
• Step 4: The impact of cost of corrosion is measured against seven management parameters.

In applying the steps above as per a CKM scheme, a suitable CM approach must also be taken. This CM approach may opt to use any CM model available, from the CM model suggested by BP to that suggested by Total and the like. As we have mentioned earlier, a CM approach as such will be a technical matter and has been discussed in previous sections.

However, regarding the steps mentioned above, Step 4 needs to be explained in more detail; in fact, we need to specify what these seven parameters are and how they are (or can be) related to a CKM model.

The seven parameters of management are as follows.

1. Budget: When based on a combination of economy models related to the estimation of cost of corrosion, it was found how significant the cost of corrosion in the plant is, then it is decided how much it is logical to expect this cost to be lowered. It must be noted that as corrosion is thermodynamic, it is impossible to bring the corrosion cost down to zero. It is generally believed that up to 37% of the cost of corrosion can be recovered. Therefore, the remaining (or a percentage of the remaining) estimated recovery cost must be taken by the management as the budget necessary to manage corrosion. As an example, if in year zero, the economy models showed that for a particular plant the cost of corrosion is, say, $100m, then it must be planned to bring down this cost to, say, $70m. It is possible to take, say, $10m as the required budget to manage corrosion to save on later corrosion costs and have a net profit of at least $20m. We take it as self‐evident that saving $30m cannot be expected to happen overnight and it requires careful planning (as per reference [16]; in Kuwait cost of corrosion in 1987 was 5.2% of the GDP, and was lowered to 1.7% of the GDP in 2011; it took 24 years for this country to lower cost of corrosion by 3.5%).
2. Human Resources (Expert Team): Based on management decision fighting against corrosion where management becomes serious enough, a team of experts will be necessary. There are three ways to handle this requirement; (i) employing corrosion experts (ii) employing an experienced consultant, or (iii) training the existing staff without going through the costs associated with previous options. If options (i) or (ii) are to be selected, for each or both options there may be a need to find the best possible solution as per existing regulations, based on the emergency of the case. In some countries, it may not be easy to create a position for a corrosion consultant to a refinery or a power plant simply because there is no position defined. It is then very important to bear in mind that any CM model that will neglect such cultural facts is to be doomed as a global recipe to treat corrosion.
3. Training Department: It is always a familiar policy by the industry to cut the expenses that may seem extra. It is quite expectable for a company not wanting to employ new person power or consultant(s) simply because it is seen as an extra cost. It is in this regards that training of existing staff may be put forward. The training department must then be very sensitive to the training programs it is planning, because most training departments have a passive rather than active role; they do not advise or publicize the available courses, but prefer to work based on the feedback they receive from the personnel. An example is that the training department may never think that a course in galvanic corrosion (particularly galvanic corrosion, CUI, or atmospheric corrosion) is necessary for their colleagues. The most they think of is to offer a general course in corrosion. The duty of the training department is to continuously seek new topics of interest and use to the present and future operation scheme of the plant, not just wait until they have a request. To avoid and prevent any industrial nepotism, the required topic and industry skills both must be required. Our readers must note that the instructor is being called for an industry case which is far different from an academic research interest, therefore the invited trainer must ideally have both academic qualifications and trackable industry experience. One may not have very distinctive academic degrees (a BSc will suffice), but in return they must have at least 20 years of experience. Dealing with various corrosion processes does need a robust theoretical background, for example, not to call microbial corrosion as water corrosion, asbitterly reported by Tatnall [34].
4. Research (University‐industry Gap): It is a bitter fact in many countries – perhaps with the exception of some Western countries – there is a huge gap between academia and industry, especially when it comes to corrosion. This author firmly believes that, at least in the field of corrosion, it is the industry that must be the leading force for research. Even very advanced research must come from industry needs and not just out of curiosity. Therefore, for a given plant it is necessary to be backed with a robust research scheme that will not only clarify corrosion reactions involved but the geometry among them. One very essential tool in conducting research is using TRIZ; the concept of TRIZ is discussed in Chapter 5 of this book, however what can be very briefly said about TRIZ is that it is an algorithm for innovation. By learning TRIZ and its principles, methods, and laws, the likelihood for achieving innovative results will be highly increased.
5. Information: There is a vast difference between data and information, as we said earlier. To process the data obtained from field measurements and convert it into information useful enough to create an idea about the current status of the corrosion system and what must be done about it in the future, both updated theoretical knowledge and field skills are needed. In addition to this aspect of information, it is vital to have a written procedure in place to lessen “dark information” and increase “white information” [5]. Dark information is the knowledge and skills hidden in people's minds and their own notes, and therefore so personalized that access to it is impossible (or too difficult) for others to understand. White information, on the other hand, is what is written and accessible by everyone. An example of dark information is verbal information, and examples of white information are standards, recommended practices, and the like. To deal with corrosion, the information must be shared and easy to access so that no time will be wasted on activities that can be branded as re‐invention.
6. Energy: In this context we use energy equivalent to motivation. Management has to deal with people and as such, they need to be motivated for the job they are going to do. It is necessary to motivate the people involved in the management of a corrosion scheme to feel that no matter their expertise – whether technical, such as engineering or non‐technical, such as management – they are part of a project that is very significant. Perhaps one way of doing this is to ensure them that if next year there is a decrease in the cost of corrosion, they will all receive a bonus! Any measures that can be used to serve the target of getting motivation and so‐called positive‐energy is of extreme importance, as there are at least nine components of a working place that will render it stressful to the employees (Figure 3.15).

   

The nine components that can cause restlessness and stress in a workplace can be described as below:

1. No Empathy: Managers are disconnected from their employees in terms of not being able to relate to them. The wall around mangers will not allow their employees to feel attachment toward their managers.
2. No Equilibrium: Working hours and family hours are not recognized. There is no distinction regarding non‐working hours for the employees, so their private lives can be severely affected by the long hours and what is imposed on them.
3. Competition: In this context, competition must not be viewed in its positive meaning. The positive meaning is when employees are in competition with each other for the good of the company. Here, however, competition is between employees themselves where methods used are not healthy. Competition in this regard can be lead to the collapse of the company, as does not aim toward advancing the company, but against other individuals.
4. No Transparency: There is no transparency about responsibilities and what is being applied. No one is aware who is doing what and who to go to for an explanation. As the responsibilities are not well defined, there is no way to distinguish where one's responsibility begins or ends.
5. Too much red tape: There are so many rules, regulations, and procedures that in reality what they do is lead to confusion. There is no opportunity to let people think and act freely, and the boundaries serve more to limit them than providing clear responsibilities.
6. No Organization: Everyone does his work in the way he thinks is correct. There are basically no measures that define where and when a job or a responsibility starts and how it must be carried out.
7. Dictatorship: In an unhealthy workplace, what the managers say is the law and everyone must follow. There is no room for critical thinking or constructive criticizing. The manager orders and then does not bear the responsibility for issues, and no one is allowed to question their decisions.
8. Just Punishment: One of the ways by which motivation can be constructed or re‐shaped in accordance with the needs and aims of the company is by a reward‐punishment system. Employees are promoted or receive a bonus for what they do that is favorable to the company, and are punished (such as fined, delaying promotions, or being fired) for what they do to harm the company, whether consciously or not. However, if instead of a dual reward‐punishment system, we rely only on only one system, the employees will soon find their working conditions unbearable and will look for opportunities elsewhere and possibly sue their previous workplace.
9. Slavery: There is no defined relationship between the management and the employees so that management behaves with their employees in any way they wish. More or less, the management assumes that their employees are like slaves to them; they may talk down to them, treat them poorly, or as lesser than themselves, whether skilled or not.

The nine components above may seem somewhat exaggerated, especially to Western readers, but this author can assure his readers that his presence in many industries around the globe have proved to him that these issues do exist.

While the nine components shown in Figure 3.15 can be related to any activity in which human beings are involved in a workplace, when it comes to CKM it becomes even much more important. One thing which often seems to be forgotten or overlooked by integrity managers and CM professionals when it comes to management of corrosion, and is a very important factor in this context, is how the members (both technical/engineers as well as technical/technicians and non‐technical, administrative colleagues) of the plant and/or company at which CKM is to be carried out need to adjust themselves concerning having knowledge about corrosion, however small or limited this knowledge may be.

The issue of corrosion within a context related to CKM is like knowing first aid; you don't need to have in‐depth knowledge of medical skills but you need to know just enough to see the essential needs. All personnel must be trained about corrosion and they must go through a carefully designed motivation system. While the level of education will be different for an engineer than an office clerk, it is something that must be determined by experts and fairly discussed with the training department of the plant/company, but the motivation program is something that would definitely require the help of an expert in this field. This expert most of the time is not an engineer but a psychologist with intense experience about people working in industries.

10. Time: What is meant by the context of time is not just completing jobs on schedule, but the entire plan. It is very important to know that a CKM scheme must start from year zero and go on for three years, at least in phases. The entire timing of the project should be like the one presented below, Figure 3.16.

The model suggested here consists of three territories:

• Blue territories: Phase 1 to Phase 4. In this territory, preparation for selection and application of corrosion cost models, as well as data acquisition and analysis to arrive at information are performed. What is meant by information here is a figure that shows direct cost of corrosion for the plant.
• While territories: In these territories, that are alternatively called waiting periods of 24 and 36 months, recommendations suggested by experts for lowering corrosion costs are applied.

  

• Yellow territories: These are the periods during which the recommended CC strategies and tactics, and the results obtained from them, are examined and analyzed.

In more detail, the following can be said: phases of the CKM scheme given in Figure 3.15 are:

• Phase 1: Selection of the economic model(s) (1 month).
• Phase 2: Preparation and modeling based on provided data (12 months).
• Phase 3: Application of the model(s) in terms of data collection (12 months).
• Phase 4: Quantification of the data into information (12 months).

The above four phases (Blue territory) as mentioned above deal with selection, preparation, application, and results.

After phase 4, there must be a waiting period that we have chosen for our model to be two years (24 months). During the waiting period, within six months (month 61 to month 67), re‐measuring corrosion cost model(s) is carried out. This is Phase 5 and is shown in yellow; Phase 5 can be called short‐term feedback. It is during this yellow territory that the initial results of recommended measures against corrosion are taken into consideration and their effects on corrosion cost are being evaluated. In these periods, it is possible to re‐use the models that were developed during the blue territory. To keep repeatability of the models and consistency of the results, it is advised to use the same models used for the blue territory for the yellow territories.

Phase 6 starts right after the quick feedback period and is a waiting time of 36 months. Phase 6 can alternatively be called mid‐term feedback. Phase 6 is important in the sense that during this phase the assets are still in their pseudo‐FFS state and the assumption is that during Phase 5 have all been applied. In other words, if the equipment has survived the short‐term feedback period and Phase 5, then this implies that they must have been in conditions good enough to have arrived in the mid‐term feedback phase.

Phase 7 is a 12‐month period, dedicated mainly to documentation and final report preparation based on the results obtained from the short‐term and mid‐term feedback periods. Each feedback period will serve to show if the CM practices performed had any effect on corrosion cost as a part of a CKM scheme.

Although the two white time phases of 24 and 36 months are included in the entire scheme of a CKM project, they are excluded from it from a cost‐management point of view. Therefore, the actual timing of the project in this example, not counting the waiting periods, will be 54 months or 4.5 years.

It is essential to note that changes to be made to seven management parameters must be done after short‐ and mid‐term feedback periods.

For a typical project as such, the help of economists is necessary in addition to engineers. In addition, ecology experts will be needed if indirect cost of corrosion (for example limited study on the impact of corrosion on environment) is also to be regarded.

Obviously, the example given in Figure 3.15 is based on several assumptions that may not be true for a given plant. For example, based on the existing corrosion awareness culture, the time length of each phase can be shortened. However, it is strongly advised not to omit the waiting periods. These periods can be made shorter but they must included in such a way that they take at least six months.

CKM has some features that need to be addressed here:

1. CKM is to be useful mainly for Greenfield projects which are in their pseudo‐FFS conditions and thus already experiencing corrosion.
2. CKM looks on both economic and ecologic sides of corrosion and therefore contrary to any CM scheme, a CKM scheme could take much longer. The main reason for this is in very few plants worldwide it is possible to find a corrosion cost scheme that has been advised by economists and executed by engineers. Equally rare is to find an ecological model for a given plant in which corrosion and its role has been highlighted.
3. CKM like CM is a part of a more encompassing management of corrosion program. The feedback taken from CKM studies, in both economy and ecology, must be carefully taken into consideration. Management of corrosion is a holistic approach and being as such, it requires that its framework also considers not only technical aspects of corrosion (such as research) but also non‐engineering aspects as well, such as issues related to human resources and training.

CKM has four principles:

• Principle 1: Corrosion system definition; this topic in terms of being able to define CINS and/or COFS has been covered previously in this chapter.
• Principle 2: Transparency; this is a legal side of CKM. According to this principle, the business owner as well as the consultant or the project manager for a CKM project agree to reveal what aspects of finding to the professionals outside of the plant and the common people who have no technical information or background about the consequences of corrosion in terms of the costs it imposes. If the outcome of corrosion in terms of environmental impact is something that would affect people living nearby, there must exist regulations that would clearly determine how the obtained results from a CKM approach become known to others. In this regard, while CM could be an internal affair of the plant or company, CKM has both an internal affair side (rearranging of seven management principles in terms of making corrosion cost more affordable) and an external affairs side (how to share the findings with other colleagues working in the same industry as well as how to deal with the information gained in terms of legal and publicizing terms). It is a bitter fact that in some countries, speaking about the extent of corrosion‐related catastrophes is taboo. This is even true for some Western reputable companies (the way some high‐ranking managers reacted to the oil spill disaster in Prudhoe Bay, for instance). For example, water authorities are using many cast iron pipes for carrying drinking water, and this water is also to be disinfected by hypochlorous acid. Recently [35] it has been discovered that upon reaction with the disinfectant agent, cast iron releases toxic compounds of chromium that could lead to serious health problems such as cancer. What should the water authorities do with this finding? Can they share it with their colleagues? Can they share it with potentially affecting people? If the answers are yes, then to what extent must this sharing process continue? If this water authority company had been located in another geography, could we expect not to even hear about the problem and the possible underlying corrosion mechanism in the first place? It is because of these and similar questions that we believe having a CKM scheme along with a proactive CM is an essential part of any management of corrosion program that wishes to be taken seriously and become successful.
• Principle 3: Use of Information; although we have previously discussed about dark and while information types, it is also worth repeating that a CKM scheme must also look at creating a systematic use of existing information (both dark and white) as well as creating information accessible to everyone, as per protocols and regulations.
• Principle 4: Modeling; what is meant by modeling is that the CKM scheme must have the potential of using mathematics in order to construct mathematical models that later on could serve as the main platform to produce specialized software. While modeling certainly has limitations such as, but not limited to, the necessity of making assumptions to make the mathematics simple enough to become applicable to the system to be considered, it certainly has undeniable advantages in explaining the present state of a system and predicting its future. Assumptions, such as initial and boundary conditions, that are necessary to make a model may seem to simplify the system – and this is one of the defects always brought up by many – it is also an important feature of any mathematical modeling procedure.

Below we will introduce a mathematical procedure we have developed based on the mathematical modeling work by Schouten and Gellings [36]. This model introduces a mathematical tool that is called Corrosion Protection Factor, or c.p.f. The model can be applicable to any given CM approach to evaluate the usefulness of CM techniques frequently used. We have explained this model and how it can be applied elsewhere in one of our previous publications [12], but due to its very important features we will very briefly discuss the main features here.

Schouten and Gellings model, or as we have briefly named it, S‐G model, looks at quantifying the best CM practice in terms of a mathematical algorithm that will combine frequency of use of certain CM measures (such as cathodic protection, coating, use of chemicals, etc.) with expert opinion of how useful these methods are when applied to a certain case of a corrosion system. In the example we have discussed in reference [12], we used a subsea pipeline example on which five CM measures, namely cathodic protection, coating, corrosion allowance (in terms of getting a “thicker” pipe), application of inhibitors, and application of biocides had been suggested as the main measures. Three experts are asked to evaluate both the usefulness and frequency of use of each method by answering a questionnaire. Based on overall opinions of the experts they are branded as optimistic, moderate, or pessimistic. For instance, the expert being branded as pessimist may have been of the opinion that most of the CM measurements are useless, less useful, or not frequently used, and the like. These opinions are quantified and certain c.p.f. percentages are calculated. The obtained c.p.f. values are matched with NACE references that define low, moderate, high, and severe corrosion categories, and based on that the average of c.p.f. values we calculated and compared with required ranges for which a given CM scheme can be called effective. In the example of the subsea pipeline and the CM measures taken against MIC management, the overall score of c.p.f. was 73.5% that corresponded to a “moderate corrosion management scheme.”

Based on the c.p.f. model above, the CKM scheme can decide how well the applied corrosion measures are in inducing corrosion protection, and thus their effect on overall direct cost of corrosion. The costs imposed on the system by the available corrosion measurement methods and the level of protection they offer will then be an important decision‐making factor in choosing the most feasible corrosion protection option. This, when joined by the impact of corrosion cost, can yield in a multilateral approach toward corrosion in a plant or in any given industry.

An incredibly significant side of any CKM is to have a say regarding indirect costs of corrosion, of which cost to environment could be the most significant. In our previous works [5, 12], we have tried to address an approach that will fill the existing gap between corrosion specialists and environment experts. Despite all these, there is no model that can be used to describe the present state of the environment when the assets are in their pseudo‐FFS state, to the best of our knowledge.

However, we believe it is necessary to explain a point that can result in confusion; study of environmental factors on atmospheric corrosion, for example, is not what is meant in this context by the mutual impacts of corrosion and environment. As reported by Mattsson [37], ISO 8044 defines corrosion as “Physicochemical interaction between a metal and its environment which results in changes in the properties of the metal and which may often lead to impairment of the function of the metal, the environment, or the technical system of which these form a part … [where] this interaction is usually of an electrochemical nature.” Based on this definition, corrosion can also induce changes (impairment) to the environment. It is then this aspect of corrosion that has its impact on environment, that must be taken into consideration as a model capable of explaining the present and predicting the future of environment components (water, air, and soil) in terms of the effects corrosion can create on them.

While in our opinion a very important item in calculating the indirect cost of corrosion is its imposed costs on the environment, there are obviously other cost items that can be included under indirect cost title, such as but not limited to, overtime of production or overdesign [11]. There are also items whose costs must be included in any corrosion cost model. Normally, it is assumed that the indirect cost of corrosion is roughly equal to its direct cost; obviously, this is an incorrect assumption. To further illustrate an example of indirect cost of corrosion and how complicated it can be take the below example.

It is known that every 90 seconds one ton (1000 kgs) of steel corrodes, and to produce 1 ton of steel, between 6 to 7 tons of water is required [38]. It is then not too candid an assumption if we assume that every 90 seconds, 6000–7000 kgs of water is being wasted due to corrosion. This figure means that within one year more than 2 m liters of water per kgs of steel are lost due to corrosion. Obviously, the amount of water which is used for steel production, i.e. 6000–7000 kgs (liters) of water cannot be changed. However, the more we save on the water per kgs of steel corroded, by reducing the amount of corroded steel we will obviously save in wasted water. The cost thus saved (or rather, in case of inappropriate management of corrosion scheme, the cost thus imposed on the system) is also an indirect cost that corrosion can be lead to.

Any model that is to handle the indirect costs of corrosion must also take into consideration the very complicated nature of these costs. It may be wise to first simply choose one area in which an easily workable model can be developed. For instance, if the model is to quantify the corrosion impact on ecology, it can simply concentrate on its impact on only one component of environment; for example, water and as a subcategory, only seawater. The model may, for example, try to relate the number of failures in which corrosion has been documented, to be a major player with the existing models that consider the effect of such impacts on how seawater is being affected. An example of studying the impact of a regular CM measure (cathodic protection) on the marine environment [39] or similar studies, can be taking the required building materials to create an assessment model to consider indirect corrosion impacts (including costs) to be modeled and calculated.