Corrosion represents one of the most serious noticed in the industrial world especially in petrochemical, petroleum, power plants, etc. Billions of Dollars are lost yearly due to the affect of corrosion in the world. General Corrosion Galvanic Corrosion Concentration-Cell Corrosion Intergranular Corrosion Stress Corrosion Cracking Pitting

1. FIN 624 Fundamental of Industrial Corrosion
Final Presentation Submitted to The Academic Department
Of the School of Science and Engineering
In Partial Fulfillment of the Requirements
For the Doctorial Degree in Mechanical Engineering
ATLANTIC INTERNATIONAL UNIVERSITY
Yasir Dhaif Mahdi Alnaseri
ID# UD67080SME76152
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2. Corrosive Environment
2

3. Corrosive Environment
 Many parameters could seriously affect the material where it is in a
specific environment.
 The effects may make significant changes in the chemical
composition of the material.
 Corrosion environment can be classified into two categories based on
the type of environment:
- Natural Environment (rain, snow, humidity, marine
environment, etc.)
- Harmful People Made Environment (road salts, air pollutions,
industrial emission, acidic rain, etc.)
3

4. Corrosive Environment
 Corrosive Environment can be categorized into several kinds
depending on its nature, such as:
- Atmospheric,
- Soil,
- Water,
- Acidic,
- Alkaline,
- and the combination (mixing) of all the above types.
 Corrosion represents one of the most serious noticed in the industrial
world especially in petrochemical, petroleum, power plants, etc.
 Billions of Dollars are lost yearly due to the affect of corrosion in the
world.
4

5. Corrosive Environment
Characteristics of The Corrosive Environment
- Degree of alkalinity or acidity
- Electrochemical potential
- Temperature of the environment
- Flow rate of the fluid
- Concentration of the corrodent
- Biological organism
5

6. Corrosive Environment
Figure 1. Effect of pH Vs. Corrosion Rate.
Adapted from Biplob Kumar Biswas From Jessore University Of Science &
Technology(JUST),Bangladesh, 2015, retrieved from
https://www.slideshare.net/rayhan_u01/corrosion-engineering-54230652
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7. Corrosive Environment
Figure 2. Electrochemical Potential Effects
Vinod Kumar Khanna, Humidity and contamination effects on electronics,
Published March 2017 , Copyright © IOP Publishing Ltd 2017,
https://iopscience.iop.org/book/978-0-7503-1155-7/chapter/bk978-0-7503-1155-7ch15
7

8. Corrosive Environment
Figure 3. Flow Rate of The Fluid Effects
Prof. T. K. G. Namboodhiri, The presentation deals with our study on the velocity
affected corrosion of a line-pipe steel, API-X52 in sea water environment, Published
on December 2nd, 2009, https://image.slidesharecdn.com/velocity-
assistedcorrosionofapix-52steelin3-091202084016-phpapp01/95/velocity-assisted-
corrosion-of-api-x-52-steel-in-3-5-728.jpg?cb=1259743284 8

9. Corrosive Environment
Figure 4. Concentration of The Corrodent Effects (Chloride as example)
Prawoto, Yunan & Ibrahim, Khaled & wan nik, wan sani. (2009). Effect
of ph and chloride concentration on the corrosion of duplex stainless
steel. Arabian Journal for Science and Engineering. 34.
9

10. Corrosive Environment
Figure 5. Biological Organism Effects
Javed, Muhammad Awais & Neil, W & McAdam, G & Wade, Scott.
(2016). MICROBIOLOGICALLY INFLUENCED CORROSION OF
COPPER AND ITS ALLOYS – A REVIEW.
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11. Corrosion Definition
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12. Corrosion Definition
There are several definitions for the corrosions, but they give the same
meaning and understanding. Corrosion is:
 The process of deterioration of a substance due to chemical, electrochemical
or other reactions takes place on the surface of the substance.
 Or, a natural process, which converts a refined metal to their more stable
oxide.
 Or, a deterioration of a material due to the electrochemical reaction between
the material and its environment.
 Or, the degradation of a material due to the interaction with the surrounding
environment or medium. 12

13. Corrosion Definition
Figure 6. Corrosion Example
Forsyth, P & Robert, D.J. & Rajeev, Pat & Li, Chun Qing. (2014).
Codified methods to analyse the failures of water pipelines: A Review.
13

14. Corrosion Mechanism
Based on the mechanism of corrosion, corrosion can divide into
two types:
 Electrochemical Corrosion (Electrolyte is required to preform this type)
 Chemical Corrosion (Electrolyte is not required)
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15. Corrosion Mechanism
 Electrochemical Corrosion:
 It called also Wet Corrosion, Aqueous Corrosion, and Low Temperature
Corrosion.
 Occurs through the formation of cell.
 Happens only on the heterogeneous metal surface.
 Non-uniform corrosion.
 It takes place when the medium temperature below 204 C.
 Corrosion products accumulates on the cathode.
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16. Corrosion Mechanism
Four factors should be available to produce the electrochemical corrosion:
1. Metal loss must be occurred.
2. Electrons must transfer from another metal.
3. Reaction should be taking place.
4. The electrolyte is mandatory as a transfer medium for the
consumed ions.
Electrochemical Corrosion
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17. Corrosion Mechanism
Example 1:
In the petroleum refining industry, the corrosion takes place by the
electrochemical corrosion. The mechanism of this corrosion is very complicated
because the electrodes are not connected by wire. For example, inside the
carbon steel pipe, there is innumerable microlevel of Anodes and Cathodes cells
represented by Iron (Fe Anode) and Iron Carbide (Cathode Fe3C); at this point,
each metal is usually conducted of an electron, that is mean, only the electrolyte
medium is required to complete the life cycle of the corrosion process inside the
carbon steel pipe. Crude oil, waste-water, petroleum residue, and row water
illustrate the most electrolyte fluids in the Oil and Gas industry.
Electrochemical Corrosion
17

18. Corrosion Mechanism
Example 2:
When the pure metal works at two different temperatures.
Temperature difference may affect the metal so that at one will be Anode
and at the different will act as Cathode. Moreover, the electrolyte
concentration may play critical factors in the electrochemical corrosion.
This factor directly affects the grain boundary of the pure metal or
material, causing corrosion when the metal or the material surface in-
direct contact with the electrolyte.
Electrochemical Corrosion
18

19. Corrosion Mechanism
Figure 7. The Electrochemical Corrosion
qi, Wang & Jia, Y. & Wang, M. & Qi, Weihong & Pang, Yong & Cui, X. & Ji, Wenhai &
Yi, Jiang. (2015). Synthesis of Cu2O Nanotubes with Efficient Photocatalytic Activity
by Electrochemical Corrosion Method. The Journal of Physical Chemistry C. 119.
10.1021/acs.jpcc.5b06213.
Electrochemical Corrosion
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20. Corrosion Mechanism
Chemical Corrosion:
 It is also called Dry Corrosion and High-Temperature
Corrosion.
 Takes place by direct chemical attack.
 Happens on the heterogeneous and homogeneous metal
surface.
 Uniform corrosion.
 Occurs above the dew point of the chemical fluids or
204 C.
 Corrosion product accumulates at the spot.
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21. Types of Corrosion
 General Corrosion
 Galvanic Corrosion
 Concentration-Cell Corrosion
 Intergranular Corrosion
 Stress Corrosion Cracking
 Pitting
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22. General Corrosion
 It called general corrosion or uniform corrosion
 Corrosion proceeds uniformly over the metal surface
 The anode areas move to different locations until the entire
metal surface become anodic at the same time
 The corrosive environment plays a critical factor in the
corrosion rate such as the motion relative to the metal
surface, temperature, concentration, acidity, and etcetera
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23. General Corrosion
Figure 8. General Corrosion
Alhaboubi, Naseer. (2014). PERFORMANCE OF CATHODIC PROTECTION FOR PIPE LINES. 10.13140/RG.2.1.2157.2884.23

24. Galvanic Corrosion
 It called galvanic because the entire system behaves as a
galvanic cell.
 It takes place when the dissimilar metals are in electrical
contact in an electrolyte.
 The less noble metal is attacked to a greater degree than if it
were exposed alone.
 Usually appears as furrows or troughs on the corroded metal
at the point of contact with the more noble metal.
24

25. Galvanic Corrosion
Figure 9. Galvanic Corrosion
Wensley, Angela & Christie, Dave. (2006). Corrosion of evaporators. 2006.
25

26. Concentration-Cell Corrosion
 It is also called Crevice corrosion.
 Concentration-cells are formed whenever the dissolved oxygen is
not uniform throughout the entire solution.
 When two dissimilar metals joint together cause deterioration, so
do different conditions within the electrolyte.
 It happens due to various substances in the solutions or to varying
concentrations of these substances.
 In general, Metal in more concentrated solutions is anodic to
metals in contact with diluted parts of the solution.
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27. Concentration-Cell Corrosion
Figure 10. Concentration-Cell Corrosion
Farotade, Gabriel & Popoola, Patricia & Popoola, Olawale. (2016). Computational
Analysis of System and Design Parameters of Electrodeposition for Marine
Applications. 10.5772/62376.
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28. Intergranular Corrosion
 Consists of a localized attack along the grain boundaries of a metal or alloy.
 The corrosion can proceed to the point where whole grains of metal falls away,
and the metal loses its strength through a redaction in cross-section.
 Improper heat transfer or heat from welding that causes the precipitation of
alloy components at the grain boundary is the usual cause of this type of
corrosion.
 The precipitation causes a depletion of corrosion-resisting elements in the area
surrounding the grain boundary, and the area becomes anodic to the remainder
of grain.
 This form of attack is most familiar with austenitic steels.
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29. Intergranular Corrosion
Figure 11. Intergranular Corrosion
Du Toit, Madeleine & van Rooyen, Gerrit & Smith, D.. (2007). Heat-Affected Zone Sensitization and Stress
Corrosion Cracking in 12% Chromium Type 1.4003 Ferritic Stainless Steel. Corrosion. 63. 10.5006/1.3278392.29

30. Stress Corrosion Crack
 It occurs in weldments when susceptible microstructure, surface
tensile stresses, and corrosion media are simultaneously present.
 It often progresses rapidly and is more common among alloys than
pure metals.
 It leads to unexpected and sudden failure of ordinarily ductile metal
alloys subjected to tensile stress, especially at elevated temperatures.
 The heat or energy input influences the weld deposit's size and
geometry, welding parameters, and procedures that affect the
amount and distribution of residual stress present in the weld. 30

31. Stress Corrosion Crack
Figure 12. Stress Corrosion Crack
Rudling, Peter. (2007). Welding of Zirconium alloys. Skultuna Adv.
Nucl. Technol. Int. Eur. AB. 8-9. 31

32. Pitting
 It takes place due to the reduction of the protective thin passive
oxide film.
 It represents a type of localized corrosive attack.
 It results from a concentration-cell formed from variations in a
solution composition in contact with the metal.
 The pit acts as an anode supported by surrounding large cathodic
areas.
 When the solution or the material combination, or both, reach a
potential that exceeds a critical value termed the pitting potential. 32

33. Pitting
Figure 13. Pitting
Honarvar Nazari, Mehdi & Shi, Xianming. (2018). Vehicle Risks of
Winter Road Operations and Best Management Practices.
10.1002/9781119185161.ch12.
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34. Method to Control Corrosion
There are five principle methods to control corrosion:
 Material selection
 Coating
 Inhibitors
 Cathodic protection
 Design
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35. Material Selection
 Material divided into two parts depending on its corrosion
behavior: the high corrosion resistance of noble metals (such as
gold and platinum) and the low corrosion resistance (such as
sodium and magnesium).
 The material selection represents a key factor, especially when
the economic issues are considered part of the design criteria.
 Corrosion behavior of the environment, corrosion rate, and
corrosion resistance of the metals illustrate the principal factors
considered in material selection for the optimum design.
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36. Coating
 The corrosion protection by coating represents one of the
most efficient methods of metal protection.
 Coating protection can be categories into two groups:
metallic and non-metallic.
 Coating layers (Which applied to the surface of an object) is
responsible for isolating the material surface from the
corrosive environment.
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37. Cathodic Protection
 Cathodic protection is a widespread way that widely appropriates to
protect the material against corrosion.
 This technique works on converting the active areas on the object (a
metal) surface to passive.
 An object works as a cathode of an Electrochemical cell.
 There are two practical application methods to achieve cathodic
protection: an impressed-current system and a sacrificial-anode system.
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38. Design
 An object design can eliminate several parameters that may lead to
corrosion that could reduce the time and cost of repair and damage
due to the corrosion.
 Corrosion damage is anticipated, the object design can provide
maximum interchangeability of critical components and
standardization of parts.
 The interchangeability and part standardization are essential,
especially in the regions that required periodic cleaning and
maintenance.
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39. Factors Influencing The Cost
Corrosion
 Applied current technology
 Deferred maintenance
 Increased performance requirements
 Technology transfer
 Extensions of useful life
 Research and development
 Environmental regulations
 More hostile environment
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40. Factors Influencing The Cost
Corrosion
 Corrosion costs are decreased by the application of available corrosion technology,
which is reinforced by technology transfer.
 New and enhanced corrosion technology results from research and development.
 The proper application of ways to control corrosion reduces the cost of corrosion.
 Corrosion costs tend to increase with such factors as deferred maintenance and
extended the useful life of building and equipment.
 Increased corrosion casts are realized when higher-performance specifications and
more hostile environments are encountered.
 Government regulations lead to a significant increment in corrosion costs.
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41. Diagnosis of Corrosion Failures
Several Techniques apply to monitor and diagnosis the corrosion
failures in industrial life, such as:
 Visual and microscopic testing of the corroded surfaces and the
microstructure.
 The chemical analysis of the metal, corrosion products, and bulk
environment.
 NDT or NDE evaluation methods.
 Corrosion testing techniques.
 Mechanical testing techniques.
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