The battle against rust and corrosion is an ongoing challenge in various industries and applications. The destructive effects of corrosion can result in significant financial losses and safety hazards. To combat this problem, corrosion inhibitors have emerged as a crucial preventive measure. In order to properly deal with corrosion and choose the best way to prevent corrosion, it is better to get to know the types of corrosion and corrosion definition first.
in the second stage, we will discuss how anti-corrosion can help various industries to preserve their metal surfaces from the harmful effects of corrosion. Tasfyeh group provides high-quality corrosion inhibitors (CIs) to assist you in maintaining your assets.
Our corrosion inhibitor are tested and used in middle east Iraq, Iran, Azerbaijan, Kazakhstan and CIS countries.
1. Types of Corrosion
Before delving into the world of corrosion inhibitors, it is essential to understand the different types of corrosion that can occur. Each type of corrosion has its unique characteristics and mechanisms. Let’s explore some of the most common types of corrosion:
1.1 Uniform Corrosion
Uniform corrosion, also known as general corrosion, is the most common type of corrosion. It occurs when the metal surface corrodes uniformly over its entire exposed area. This type of corrosion results in a gradual loss of metal thickness and can be caused by exposure to moisture, oxygen, or chemicals.
1.1.1 Mechanism:
- Anodic Reaction: At the metal surface, metal atoms lose electrons and become metal cations, which then dissolve into the aqueous environment. This is oxidation and occurs at the anode sites of the corroding metal.
- Cathodic Reaction: At separate sites on the metal surface, a reduction reaction typically happens, where hydrogen ions in the water or oxygen gas from the air gain electrons to form either hydrogen gas or hydroxide ions. This process occurs at the cathode sites.
- Movement of Ions: Metal cations move away from the anode and attract negative ions, creating a corrosion cell.
- Electron Flow: Electrons flow from the anode to the cathode through the metal, facilitating the above reactions.
- Uniform Thin Layer Formation: Unlike localized corrosion, such as pitting, the product of uniform corrosion usually forms a thin layer of oxides or other corrosion products over the entire metal surface. This thin layer can sometimes act as a protective barrier slowing further corrosion, though usually, it’s not protective enough to prevent ongoing material loss.
1.1.2 Occurrence:
- In the Atmosphere: Most metals exposed to the atmosphere will undergo uniform corrosion. An excellent example is the rusting of steel.
- In Soils: Metals buried in soils with moisture and varying pH levels can have uniform material degradation.
- In Water: Components submerged in or in contact with water, especially seawater, which is corrosive due to its salt content, may corrode uniformly.
- In Chemicals: Metals exposed to acids, bases, and other chemicals can corrode uniformly if the chemical is not too aggressive.
- In Processing Industries: Tanks, vessels, and pipes used in chemical processing often face uniform corrosion if not adequately protected.
1.2 Galvanic Corrosion
Galvanic corrosion, also known as bimetallic corrosion, occurs when two dissimilar metals come into contact in the presence of an electrolyte, such as moisture or saltwater. In this electrochemical process, one metal acts as an anode and corrodes more rapidly, while the other metal acts as a cathode and remains protected. The difference between electrochemical potential is the main reason of this electrochemical process. One metal (the cathode) is protected, whilst the other (the anode) is corroded. The presence of a conductive path, such as a metal-to-metal connection, enhances galvanic corrosion.
Figure 1galvanic corrosion chart
The electrochemical reaction that occurs in galvanic corrosion follows the above table (also know as galvanic corrosion chart). Between two connected electrode, the stronger reducing agent acts as anode and the stronger oxidizing agent acts as cathode. Therefore the metal with lower standard potential will corrode and the metal with higher standard potential will protected.
1.2.1 Mechanism:
- Dissimilar Metals: For galvanic corrosion to take place there must be two different metals present. These metals have different electrode potentials—a measure of the tendency of a metal to oxidize (lose electrons).
- Electrical Contact: The two metals must be electrically connected, which allows for the flow of electrons from the more anodic metal to the more cathodic metal.
- Presence of an Electrolyte: An electrolyte, such as saltwater, must be present. This allows for the movement of ions, which is needed to complete the electrical circuit.
1.2.2 Occurrence:
- Marine Environments: The saltwater acts as an excellent electrolyte, and ships often have multiple types of metals, making them prone to galvanic corrosion.
- Underground Pipelines: Buried steel structures in contact with soils of varying compositions and moisture levels can experience galvanic corrosion.
- Plumbing Systems: Different metals in pipes and fixtures can set up galvanic cells.
- Metal Fasteners: When fasteners such as screws and bolts are made of a different metal than the metal they are fastening, they can corrode.
- Air Conditioners: The copper tubing used in the coils can undergo galvanic corrosion if it is in contact with aluminum fins.
- Automobiles: Different metals in car components can experience galvanic corrosion, especially in areas where salts are used on roads.
1.3 Pitting Corrosion
Pitting corrosion is a localized form of corrosion that leads to the formation of small pits or holes on the metal surface. It occurs in areas where the protective oxide layer breaks down, allowing the corrosive agents to attack the metal. Pitting corrosion can be highly destructive, as even small pits can lead to significant damage and structural failure.
Pitting corrosion is a localized form of corrosion that results in the creation of small holes or pits in the metal. This phenomenon is particularly insidious due to its corrosion ability to cause significant structural damage while affecting only small areas, making it difficult to detect in its early stages. Pitting corrosion can lead to eventual failure of structures and components without forewarning, emphasizing the importance of understanding its mechanism and the conditions under which it occurs.
1.3.1 Mechanism of Pitting Corrosion:
a. Breakdown of Passive Layer:
Pitting corrosion generally begins with the breakdown of a metal’s protective passive oxide film. This film can be compromised through mechanical damage, chemical attack, or by the presence of chloride ions, which are particularly aggressive towards stainless steel.
b. Initiation of Pits:
Once the passive layer is compromised, localized anodic and cathodic sites form on the metal surface. At the anodic site, metal cations are released into the solution as the metal begins to dissolve. These localized areas become anodic when compared to the undamaged surrounding metal, which acts as the cathode.
c. Growth of Pits:
The metal cations react with the surrounding water and chloride ions to form metal chlorides, which are soluble, and hydrochloric acid. This acid further catalyzes the corrosion process. The pits can become autocatalytic – meaning the conditions at the bottom of the pit are more aggressive and corrosive than at the surface, leading to faster corrosion progression within the pit.
d. Stabilization of Pits:
As the pits grow in depth and perhaps widen, they become effectively shielded from the environment, and the pit environment (pH, O2 concentration) becomes different from that of the bulk solution. This is due to the build-up of corrosion products and the restricted access of oxygen, which stabilizes pit growth.
e. Propagation Phase:
In this phase, pit growth becomes stable and may continue at a consistent rate. The interior of the pit becomes anodic, and the surface around the pit becomes the cathodic area, promoting metal dissolution within the pit.
1.3.2 Places Where Pitting Occurs:
Marine Environments:
The presence of saltwater and high chloride ion concentrations makes marine environments particularly aggressive for pitting corrosion, affecting ship hulls, offshore structures, and stainless-steel components.
Industrial Settings:
Chemical processing plants, paper mills, and water treatment facilities use chemicals that can lead to pitting in various metal equipment and structures.
Infrastructure:
Pitting can occur in reinforced concrete structures where the steel rebar is exposed to chlorides, either from de-icing salts or seawater.
Domestic Appliances:
Stainless steel kitchen appliances, pipes, and water heaters can suffer from pitting corrosion, especially in areas with hard water or chlorine-treated water supplies.
Oil and Gas Industry:
The combination of water, oxygen, and sulphides inside pipelines and storage tanks, typically found in the oil and gas industry, can also lead to pitting corrosion.
1.4 Crevice Corrosion
Crevice corrosion occurs in confined spaces or crevices, such as gaps between metal surfaces or under gaskets or deposits. The stagnant microenvironment _ like those found under washers, gaskets, fastener heads, and adjoining surfaces, where the access of the working fluid is limited_ in these crevices promote the accumulation of corrosive agents, leading to localized corrosion.
1.4.1 Mechanism of Crevice Corrosion:
The mechanism of crevice corrosion involves several stages. Initially, the metal surface within the crevice depletes in oxygen compared to the surrounding environment. Due to this difference in concentration, an electrochemical cell is established between the two areas.
- Initiation: Oxygen in the crevice is consumed during normal electrochemical reactions. Since the crevice is narrow, it’s difficult for more oxygen to diffuse into the space. The metal within the crevice becomes anodic (oxidation), while the freely exposed metal outside the crevice becomes cathodic (reduction).
- Propagation: As the reduced oxygen levels in the crevice create an anodic condition, metal ions begin to dissolve. The crevice environment becomes acidic due to the hydrolysis of these metal ions. This acidic condition further accelerates the corrosion process.
- Concentration of Corrosive Agents: The differential aeration promotes a concentration of chloride ions or other corrosive agents within the crevice, which leads to an aggressive attack on the localized area of the metal.
- Stagnation: Limited fluid exchange further compounds the problem, as the corrosive agents are not diluted or flushed away. The lack of fluid movement allows the localized chemistry within the crevice to become significantly different from the open fluid.
1.4.2 Places Where It Occurs:
Crevice corrosion commonly occurs in places where metals are joined together or where small gaps exist between parts. It is particularly prevalent in marine environments on ships and offshore structures due to the presence of saltwater, which provides a plentiful supply of chlorides. Other common sites include:
- Flanged joints where different metal components are bolted together with a gasket in between.
- Under deposits, like sediment, biofilm or corrosion product, where crevices are formed underneath.
- At lap joints, where two pieces of metal overlap.
- Under bolt and nut assemblies or rivet heads where washers are also used.
- Within or under packing materials and sealing elements, such as o-rings.
- Pipe supports, where pipes rest on or are clamped to supports, creating an area with restricted flow.
1.5 Intergranular Corrosion
Intergranular corrosion is a selective attack that occurs along the grain b
oundaries of a metal. It is caused by the segregation of impurities, depletion of certain alloying elements, or the formation of intermetallic compounds at the grain boundaries. Intergranular corrosion can result in significant loss of mechanical strength and structural integrity.
1.5.1 Mechanism of Intergranular Corrosion:
a. Sensitization:
The mechanism often begins with a process called sensitization, which typically occurs during heat treatment or welding. Stainless steel, for instance, when heated to high temperatures, can lead to the precipitation of chromium carbides at the grain boundaries if the steel is not cooled rapidly enough.
b. Depletion Zone Formation:
This carbide formation results in a chromium-depleted zone adjacent to the grain boundaries. Since chromium is the element that imparts corrosion resistance in stainless steel by forming a protective oxide layer, its absence means that the immediate area becomes more susceptible to corrosive agents.
c. Attack on Grain Boundaries:
When exposed to a corrosive environment, these depleted zones lack the ability to regenerate the passive film that protects the steel. Consequently, an electrochemical cell is formed, where the less noble grain boundary regions act as anodes and the bulk of the grain acts as the cathode.
d. Propagation:
Once this cell is established, corrosion advances along these anodic paths, penetrating deeper into the material—effectively undermining the structural integrity of the material.
1.5.2 Where It Occurs:
Intergranular corrosion often occurs in:
- Welded Joints: Heat from welding can produce conditions for sensitization at the heat-affected zone adjacent to welds.
- Heat-Affected Zones (HAZ) in Metals: Similar to welding, any processes involving the application of heat can lead to sensitization and subsequent intergranular corrosion if not properly managed.
- Stainless Steels and Nickel-Based Alloys: These are particularly susceptible to intergranular corrosion if they haven’t been properly treated to avoid carbide formation.
- Improperly Treated Metals: Any alloy that requires a post-treatment to stabilize its microstructure but hasn’t been subjected to such treatment, risking sensitization during subsequent operations or service.
1.6 Selective Leaching Corrosion
Selective leaching corrosion, also known as dealloying or parting corrosion, is a process where one element of an alloy is preferentially removed by corrosion. This type of corrosion typically occurs when the alloy contains dissimilar metals or when one metal is more susceptible to corrosion than the other. Selective leaching corrosion can lead to the formation of porous structures and weakening of the material. The most common form of selective leaching is the dezincification of brass, where zinc is leached out, leaving behind a copper-rich structure.
1.6.1 Mechanism of Selective Leaching:
- Initiation: Selective leaching begins at the microstructural level, where the alloy may have areas enriched in the less noble element due to the manufacturing process or due to inhomogeneities in its crystal structure.
- Dissolution: When exposed to a corrosive environment, the more reactive (less noble) metal in the alloy starts to dissolve. For example, in brass, zinc is more reactive compared to copper and preferentially dissolves into the surrounding environment.
- Penetration and Progress: As the less noble metal continues to dissolve, this leaching tends to penetrate into the material. It can lead to a network of channels or pores, which predominantly follow the grain boundaries of the metal.
- Residual Structure Formation: The remaining structure becomes increasingly porous and is composed primarily of the nobler metal, which is not dissolved. This can significantly reduce the mechanical strength of the alloy and alter its original properties.
- Dealloyed Layer Development: Over time, a layer of the nobler metal may form on the surface of the component, which might initially act as a protective layer. However, the underlying weakened structure might still be prone to failure due to mechanical stresses or continued corrosion.
1.6.2 Places Where Selective Leaching Occurs:
- Plumbing Systems: In domestic and industrial plumbing systems made of brass or other susceptible alloys, particularly where water chemistry can accelerate dealloying.
- Boiler Systems: In boiler systems, where the differential temperature and flow of water can cause selective leaching of weaker elements in the alloy.
- Marine Environments: In marine environments for components exposed to seawater, where the chloride ions can induce dealloying in susceptible materials.
- Process Industries: In chemical and process industries using metal equipment and piping that may be subject to corrosion due to the aggressive nature of fluids or gases in the processes.
- Historical Artifacts: In archaeological artifacts made of bronze or other alloys, which may suffer selective leaching over long periods due to environmental exposure.
1.7 Erosion Corrosion
Erosion corrosion is a type of corrosion that occurs in metals when they are exposed to a fast-flowing liquid. This process combines the physical abrasive action of the fluid with a corrosive chemical action, resulting in the accelerated loss of material from the metal surface.
1.7.1 Mechanism of Erosion Corrosion:
- Initiation: Fast-moving fluids, especially if they contain abrasive particles, initiate the erosion by wearing away the protective oxide layer that forms naturally on metal surfaces.
- Acceleration: Once the protective layer is compromised, the underlying metal is exposed to the corrosive environment (which may contain oxygen, acids, salts, etc.), leading to an accelerated corrosion rate.
- Propagation: The wear due to the fluid’s abrasiveness continues to damage the metal, exposing new fresh metal surfaces to corrosive agents. The corrosion wastage appears as grooves, gullies, wave-like indentations, or rounded holes.
1.7.2 Factors Influencing Erosion Corrosion:
- Velocity and nature of the fluid (turbulent flow increases the risk).
- Temperature of the fluid (higher temperatures generally increase corrosion rates).
- Chemical properties of the fluid (acidity, oxygen levels, etc.).
- Presence of abrasive particles in the fluid.
- Type of metal (some metals are more resistant to erosion corrosion).
1.7.3 Common Places Where Erosion Corrosion Occurs:
- Piping Systems: Particularly at bends, elbows, tees, and other areas where fluid flow may be disrupted and cause turbulence.
- Heat Exchanger Tubes: High velocity, temperature changes, and the presence of corrosive agents can combine to cause erosion corrosion.
- Pump Impellers: The impeller can experience increased wear due to both the motion and the fluid it is propelling.
- Valves: Especially where there is throttling action, leading to local turbulence and increased flow velocity.
- Ship Propellers: The motion through seawater, which may contain sand and other particulates, can lead to erosion corrosion.
- Hydraulic Machinery: Any high-velocity fluid equipment with metal components can be susceptible.
- Wind Turbines: Especially those located in marine environments where the presence of salty water and high winds can contribute to erosion corrosion.
1.8 Stress Corrosion Cracking
Stress corrosion cracking (SCC) is a type of corrosion that occurs under the combined influence of tensile stress and a corrosive environment. It can result in the sudden failure of a component, even at stress levels well below its normal yield strength. Stress corrosion cracking is a significant concern in industries such as aerospace, nuclear power, and chemical processing. SCC can lead to unexpected sudden failure of normally ductile metals subjected to a tensile stress, especially at elevated temperatures.
1.8.1 Mechanism of SCC:
- Initiation: Small cracks or pits form on the metal surface in corrosive environments. The tensile stresses may be due to applied loads, residual stresses from manufacturing processes, or a combination of both.
- Propagation: Once initiated, these cracks continue to propagate through the material in the presence of tensile stress and the corrosive environment. The propagation mechanism could be anodic dissolution, in which the metal at the crack tip dissolves electrochemically, or hydrogen embrittlement, where hydrogen ions diffuse into the metal and weaken the bond between the metal atoms.
- Failure: As the crack propagates, the effective cross-sectional area of the material is reduced and the stress across the reduced area increases, which can ultimately lead to sudden and catastrophic failure.
1.8.2 Occurrence:
Stress corrosion cracking can occur in a variety of environments and is highly material specific. Some common places where SCC occurs include:
- Pipelines: SCC can affect underground pipelines, especially those that carry oil, gas, or water. Soils with high electrical conductivity can intensify corrosion processes.
- Boilers and Pressure Vessels: In power plants and industrial facilities, SCC can occur in boiler tubes due to the combined effects of tensile stress and the aggressive environments inside these systems.
- Bridges and Infrastructure: Structural components made of high-strength steel can be prone to SCC, particularly in harsh environmental conditions such as those with deicing salts.
- Marine Structures: Saltwater environments are highly corrosive and can induce SCC in ship hulls, offshore platforms, and other marine hardware.
- Aircraft Components: High stress on aircraft components due to the operational stress and sometimes chemical exposure can lead to SCC.
1.9 Corrosion Fatigue
Corrosion fatigue refers to the material degradation process resulting from the combined action of cyclic stress and chemical or electrochemical corrosion. It’s the premature and accelerated material failure due to the simultaneous effects of mechanical cycling and a corrosive environment. Corrosion fatigue can reduce the life expectancy of components significantly compared to what would be observed under the influence of either stress or corrosion alone.
1.9.1 Mechanism:
- Initial Corrosion: The material is exposed to a corrosive environment which leads to the formation of pits or micro cracks on the surface.
- Crack Initiation: Under cyclic loading, these localized defects become the nucleation sites for fatigue cracks. The presence of corrosion accelerates the initiation due to the reduced cross-sectional area and the introduction of stress concentrators.
- Crack Propagation: The cyclic stresses cause these cracks to propagate. Corrosion at the crack tips can further exacerbate crack growth by continuously generating a fresh, reactive surface for the corrosive media.
- Final Failure: Eventually, the crack reaches a critical size, and the material undergoes sudden fracture, potentially without significant plastic deformation.
1.9.2 Places where corrosion fatigue is a major concern include:
- Marine Structures: Offshore platforms, ship hulls, and propeller shafts are in constant contact with sea water, which contains salts that can cause both corrosion and facilitate fatigue.
- Bridges and Infrastructure: Structures exposed to the elements and affected by vibration and stress from traffic are susceptible to corrosion fatigue.
- Aircraft: Components are subjected to cyclic stress during takeoff, cruising, and landing, while various environmental factors can induce corrosion.
- Pipelines and Refining Equipment: Especially those in the oil, gas, and chemical industries where both stress and corrosion from fluids or gasses are present.
- Medical Implants: Devices like pacemakers and artificial joints may be subjected to body fluids which can pose a corrosive environment.
- Automotive Components: Parts such as engines, transmissions, and suspensions deal with stress and are often exposed to corrosive agents like road salt.
1.10 Fretting Corrosion
Fretting corrosion is a type of wear and corrosion damage that occurs at the asperities of contact surfaces. This damage typically happens on the microscopic level at the interface of two materials under load and subjected to minute relative motion by vibration or some other force.
1.10.1 Mechanism:
- Contact and Relative Motion: Two surfaces come into contact under load, trapping a thin layer of air or fluid between them. When the surfaces experience vibration or oscillatory motion, even of small amplitude, the protective oxide layers on the metals can be disrupted.
- Debris Generation: The relative movement causes wear particles (debris) to form as the protective oxide layers break down. This debris can be more reactive chemically than the bulk material because of the higher surface area and its freshly exposed, reactive metal surfaces.
- Oxidation and Wear Acceleration: The fresh metal exposed to the environment readily oxidizes. The wear debris further gets oxidized and the movement between surfaces may crush the oxidized particles, creating an abrasive paste. This paste accelerates the wear and creates more fresh metal surfaces, which then oxidize, perpetuating the cycle.
- Compound Formation: Metal oxides, along with other chemical compounds formed due to corrosion reactions, add to the abrasive character of the fretting zone.
1.10.2 Occurrence:
- Machinery and Engines: It happens often in machinery with bolted or press-fit components or any areas where components are subject to repeated small-amplitude movements, such as in engines or rotating machinery.
- Electrical Contacts: Fretting corrosion can affect electrical contacts where the connection is not perfectly stable, leading to deterioration of the contact surfaces.
- Orthopedic Implants: In biomedical applications, such as bone implants or joint replacements, it can occur at the interface of different materials when subjected to body movements.
- Aerospace Components: Aerospace components, which are exposed to constant vibration during flights, can also suffer from fretting corrosion.
1.11 Cavitation Corrosion
Cavitation corrosion is a process where the protective metal surface is eroded away due to the mechanical action of cavitation. Cavitation is the formation and implosion of bubbles in a liquid – typically near a moving metal surface. The collapse of these cavities or bubbles generates localized shockwaves that can cause significant damage to metal surfaces over time.
1.11.1 Mechanism of Cavitation Corrosion:
- Bubble Formation: When a liquid flows swiftly over a metal surface, the pressure of the liquid may drop sufficiently to reach or go below its vapor pressure. This causes the formation of small vapor-filled cavities or bubbles in the low-pressure regions.
- Bubble Collapse: As these bubbles are swept away from low pressure areas to regions of higher pressure, the liquid pressure exceeds the vapor pressure inside the bubbles, which causes them to collapse or implode.
- Shockwave Creation: The collapse of bubbles generates micro-jets, or shockwaves, that strike the metal surfaces with great force.
- Metal Erosion: Over time, these shockwaves can remove metal, deform the surface, and even cause the formation of pits on the metal surface. The continuous deformation also induces work hardening and leads to the formation of cracks which can propagate leading to material failure.
1.11.2 Places Where Cavitation Corrosion Occurs:
- Pump Components: Cavitation can damage pump impellers, casings, and pump vanes, especially in high-speed centrifugal pumps or where there is a sudden change in flow direction.
- Valve Seats and Discs: When valves suddenly close or when they throttle fluid flow, the changes in pressure can lead to cavitation around the valve body.
- Propellers and Rudder Blades: Ships’ propellers are also very prone to cavitation because of the rapid flow of water, especially at high speeds or during tight maneuvers. This kind of cavitation is often referred to as “propeller cavitation.”
- Turbine Blades: Hydraulic turbines in power plants may suffer cavitation, especially on the low-pressure side of the blades.
Pipe Elbows: In piping systems, especially where there are elbows or other forms of restrictions, the fluid velocity changes and cavitation may occur.
Overall, any industry that utilizes metal equipment or infrastructure and faces exposure to corrosive agents can benefit from the use of corrosion inhibitors to prevent deterioration and extend the lifespan of assets. Tasfyeh group provides a wide range of anti-corrosions in the following industries.
2. usage of corrosion inhibitor in industry
Corrosion inhibitors are used in a wide range of industries including:
- Oil and Gas Industry: The oil and gas sector heavily rely on corrosion inhibitors to protect pipelines, well casings, tanks, and other equipment from corrosion caused by the presence of corrosive fluids and gases in downhole, production and transportation of oil and natural gas.
- Water Treatment: Corrosion inhibitors are used in water treatment processes, such as cooling water systems and boilers, to prevent corrosion of metal pipes and components that encounter water containing impurities and chemicals in open or closed-circuit systems.
- Power Generation: Power plants, including nuclear, thermal, and hydroelectric facilities, use corrosion inhibitors to protect critical components like pipes, turbines, and boilers from the corrosive effects of water, steam, and chemicals.
- Marine Industry: Ships, offshore platforms, and marine equipment are subjected to harsh saltwater environments that accelerate corrosion. Corrosion inhibitors help extend the lifespan of these assets by preventing or minimizing corrosion.
- Steel industry: Corrosion inhibitors are used to prevent the corrosion of steelmaking equipment, such as blast furnaces, converters, ladles, and rolling mills. They can also improve the quality and durability of steel products, such as bars, rods, wires, and sheets.
2.1 Oil and gas industry
2.1.1 Acidizing Corrosion Inhibitors
When it comes to acid treatments like matrix acidizing, acid fracturing, acid stimulation or sand control procedures, the usage of corrosion mitigating techniques is paramount. These inhibitors play a crucial role in countering the destructive impact of highly acidic fluids that can lead to severe corrosion. Tasfyeh group takes the lead by offering a comprehensive range of top-quality corrosion inhibitors, formulated to safeguard metal components within the wellbore, downhole and coiled tubing.
In acidizing processes, the efficacy of corrosion inhibitors hinges on their ability to effectively mitigate corrosion across a diverse range of steel types. The objective is to ensure lasting protection for valuable equipment and infrastructure. Corrosion inhibitors should demonstrate stability even under the duress of elevated acid concentrations and the rigors of high reservoir temperatures.
Tasfyeh group’s Cutting-Edge Solution – acidizing
Tasfyeh Group has achieved success with its acidizing product. This innovative formulation shines among others due to its excellent performance.
It has been rigorously tested and proven to deliver exceptional corrosion inhibition under a spectrum of temperature conditions. Notably, it maintains its integrity at temperatures up to 230 F before decomposition occurs. This makes it a robust and reliable solution for the challenging conditions of acid treatments.
For more severe conditions that may involve higher acid concentrations or temperatures up to 300 F, intensifiers stand as versatile option. These intensifiers can be mixed with corrosion inhibitors and decrease the severity of corrosive media. This proactive approach ensures ongoing protection for equipment, even in sever conditions i.e., temperature up to 300 F and acid concentration up to 28%.
Advantages of acidizing product:
- Suited for strong acids and high temperatures
- Liquid form
- Versatile in varying acid concentrations
- film forming properties
- High temperature stable
2.1.2 Water soluble corrosion inhibitor
The presence of water, acids, acidic gases, high levels of oxygen, and brine creates an ideal environment for corrosion to occur. To combat this issue, water-soluble corrosion inhibitors (CIs) have emerged as a vital solution in the industry.
Corrosion inhibitors are surfactants that possess unique properties, allowing them to partition between the oil and water phases. These inhibitors have a hydrophilic group that adsorbs onto the metal surface, while the hydrophobic group forms a water-resistant organic film. This film acts as a protective barrier, preventing corrosive species from coming into contact with the metal surface. Water-soluble corrosion inhibitors offer robust film-forming characteristics, making them suitable for various metallurgies and providing excellent stability over a range of pH and temperature values. Water soluble corrosion inhibitors can protect the metal surfaces from corrosion caused by carbon dioxide (CO2), hydrogen sulfide (H2S), organic acids, oxygen, bacteria, and other corrosive agents present in the water phase. Therefore, they can act in both sweet and sour environments. Water soluble corrosion inhibitors can be classified into different categories based on their chemical composition, such as organic amines, imidazolines, quaternary ammonium salts, phosphonates, polymeric compounds, and green inhibitors.
In the oil and gas industry, corrosion poses significant risks to equipment and pipelines, leading to production disruptions and economic losses. Water-soluble corrosion inhibitors play a pivotal role in preventing corrosion-related failures and maintaining the integrity of infrastructure. These inhibitors are typically dosed continuously to maintain a steady concentration, ensuring consistent protection against corrosion without interrupting production.
Water-soluble corrosion inhibitors come in various formulations, each tailored to specific applications and operating conditions such as sour and sweet environments. These inhibitors are designed to address the unique challenges presented by different environments and metallurgies.
The formulation of water-soluble corrosion inhibitors involves careful consideration of the specific requirements of the oil production environment. Extensive research and development efforts are dedicated to creating effective inhibitor formulations that offer maximum protection against corrosion. Formulations are designed to be stable over a range of pH and temperature values, ensuring reliable performance in diverse operating conditions to protect pipeline, tanks, valves and other equipment involved in oil production.
Continuous research and development efforts of Tasfyeh group in the oil and gas industry have led to advancements in water-soluble corrosion inhibitors. These advancements include the development of inhibitors with enhanced stability, higher electrolyte tolerance, and lower dosage requirements. Formulations are continuously improved to address evolving challenges and provide more effective corrosion protection.
Water-soluble corrosion inhibitors offer numerous benefits to the oil and gas industry. By preventing corrosion, these inhibitors help extend the lifespan of equipment and pipelines, reducing maintenance costs and minimizing production disruptions. They also contribute to enhanced safety by preventing failures and leaks that could pose environmental and health risks. Additionally, the use of water-soluble corrosion inhibitors promotes sustainable operations by reducing the need for frequent replacement of corroded components.
Tasfyeh group’s water-soluble corrosion inhibitors have been successfully implemented in various applications within the oil and gas industry. From offshore platforms to pipeline systems, these inhibitors have played a vital role in protecting critical infrastructure and ensuring the uninterrupted flow of oil and gas. Case studies and success stories highlight the effectiveness of water-soluble corrosion inhibitors in mitigating corrosion-related risks and improving operational efficiency.
2.1.3 Oil soluble corrosion inhibitors
In the world of oil production, ensuring the longevity of equipment and infrastructure is paramount. Corrosion, a natural process that can lead to devastating consequences, poses a significant threat to the efficiency and safety of oil production operations. Ferrous metals are susceptible to corrosion in the presence of air and water, a process that is accelerated by the presence of H2S, sulfides, and other contaminants. Therefore as H2S increases the rate of corrosion, industries use H2S scavengers to reduce the toxicity and corrosiveness of the environment (In order to know more about H2S scavengers, production of Tasfyeh group, click here)
Oil-soluble corrosion inhibitors are a class of compounds specifically designed to prevent or mitigate the damaging effects of corrosion in the oil production process. Unlike traditional water-based inhibitors, oil-soluble inhibitors are formulated to seamlessly integrate into the hydrocarbon-rich environment, providing superior protection against the corrosive elements present in oil and gas production. Totally, oil soluble corrosion inhibitors:
- Enhanced Protection: Oil-soluble corrosion inhibitors offer a higher level of protection against corrosion due to their compatibility with the oil and gas mixture. This ensures that critical components, such as pipelines, well casings, and production equipment, remain safeguarded against degradation and premature failure.
- Cost Efficiency: By preventing corrosion-related downtime and equipment replacements, oil companies can save substantial costs in maintenance and repairs. Additionally, the prolonged lifespan of infrastructure contributes to more sustainable and economically viable operations.
- Improved Operational Efficiency: The consistent use of oil-soluble inhibitors helps maintain the integrity of production processes, leading to uninterrupted operations and optimized efficiency. This is particularly crucial in offshore environments where accessibility for maintenance can be challenging.
Through cooperation with oil companies, the Tasfyeh group has been able to assess the current problems in the oil field and, relying on its technical knowledge, provide anti-corrosion products tailored to the customer’s needs in a personalized manner.
There are many different utilities of corrosion inhibitors in oil and gas industry, such as refineries and Petrochemicals. In the oil and gas refinery, corrosion inhibitors are used to prevent the corrosion of steel reactors, columns, heat exchangers, vessels, pipes, and other equipment that are involved in the processing and conversion of crude oil and natural gas into various products, such as gasoline, diesel, jet fuel, kerosene, liquefied petroleum gas (LPG), ethylene, propylene, etc. In addition, in petrochemical production, corrosion inhibitors are used to protect the steel equipment and pipelines that are used to produce various petrochemicals from oil and gas derivatives, such as ethylene oxide, ethylene glycol, polyethylene, polypropylene, vinyl chloride monomer (VCM), polyvinyl chloride (PVC), styrene monomer (SM), polystyrene (PS), etc.
2.1.4 Hydrostatic test corrosion inhibitor
Hydrostatic test corrosion inhibitor is a chemical substance that can prevent or reduce the corrosion of metals during hydrostatic testing. Hydro-test is a process of filling a system, such as a pipe, tank, or vessel, with water and pressurizing it to check for leaks and strength. Hydrostatic testing is important for quality control and safety of various systems, especially in the oil and gas, power generation, construction, and manufacturing industries.
However, hydrotest can also cause corrosion of the metal surfaces due to the presence of water, oxygen, dissolved salts, acids, and bacteria. Corrosion can damage the integrity and functionality of the system, leading to failures, accidents, and environmental pollution. Corrosion can also reduce the quality and quantity of the products, resulting in economic losses.
Therefore, hydrostatic test corrosion inhibitors are added to the water to protect the metal surfaces from corrosion during and after hydrostatic testing. Hydrostatic test corrosion inhibitors work by forming a protective layer on the metal surface that blocks the electrochemical corrosion reaction. They can also reduce the amount of oxygen and bacteria in the water by scavenging or killing them witt biocides.
Hydrostatic test corrosion inhibitors are an essential solution for corrosion protection during hydrostatic testing. They can help ensure the quality and safety of various systems and products in different industries. For more information keep in contact with Tasfyeh group’s consultants.
2.2 Power plants
Mining and mineral processing companies need to find new and alternative water sources to meet their production needs as water becomes scarce. Sometimes, they have to pump sea water and sea water RO permeates over long distances to the mine sites to ensure enough water for daily operations. These pipelines are vital for the economic success of the mines that depend on them. To prevent corrosion damage, corrosion inhibitors are widely used to protect the key parts and maintain the long-term reliability of the infrastructure. Tasfyeh group examines the different kinds of corrosion inhibitors used in power plants, focusing on their use in neutral to alkaline conditions such as boilers, cooling tower systems, and pipelines.
2.2.1 Corrosion Inhibitors in Cooling Towers
Cooling towers are essential components in power plants, used to remove heat from the process fluids. However, the continuous exposure to water and air in cooling towers can lead to corrosion and scale formation. To mitigate these issues, corrosion inhibitors are employed in cooling water treatment.
- Scale Inhibitors
Scale formation occurs when dissolved minerals in the water precipitate and deposit on heat exchange surfaces. This can reduce heat transfer efficiency and promote microbiological growth. Scale inhibitors, such as polyphosphates, phosphonates, and acrylate polymers, are commonly used to prevent the formation of scale by inhibiting crystal growth and modifying the crystal structure.
- Corrosion Inhibitors
Corrosion inhibitors in cooling towers act by forming a protective film on the metal surface, preventing the electrochemical reactions that lead to corrosion. Different types of corrosion inhibitors are used, including nitrites, orthophosphates, silicates, and molybdates. These inhibitors can act as either anodic or cathodic corro
sion inhibitors, depending on their mode of action.
2.2.2 Corrosion Inhibitors in Boilers
Boilers play a critical role in power plants, generating steam for electricity production. However, the high temperatures and pressures in boilers create an environment conducive to corrosion. Corrosion inhibitors are used in boiler water treatment to protect the boiler tubes and other components from corrosion.
- Oxygen Scavengers
Oxygen is a major contributor to corrosion in boilers, as it reacts with metal surfaces to form oxides. Oxygen scavengers, such as hydrazine and sulfite, are added to the boiler water to remove dissolved oxygen and prevent corrosion. These scavengers chemically react with oxygen, converting it into harmless byproducts.
- Alkalinity Builders
Maintaining proper alkalinity in boiler water is crucial for corrosion control. Alkalinity builders, such as sodium hydroxide and sodium phosphate, are used to raise the pH of the water and maintain a protective alkaline environment. This helps to reduce the corrosion rate and protect the metal surfaces from acidic attack.
- Phosphate Treatment
Phosphate treatment is another common method of corrosion control in boilers. Phosphates form a protective layer on the metal surfaces, preventing corrosion by inhibiting the dissolution of metal ions. This treatment also helps to control pH and minimize the formation of scale.
Tasfyeh group produces phosphate esters with different ratios of mono and diester. The more monoester there is, the better the inhibitor can cover the metal surface (surface film) and protect it from corrosion. The surfactant’s hydrophobic tail and the amount of ethoxylation also affect its performance. They influence how well the phosphate ester can wet, lower surface tension and emulsify. Tasfyeh group’s inhibitors can be used alone or mixed with other ingredients to make them more economical.
I can make two types of anti-corrosion solutions with the phosphate esters, depending on their hydrocarbon tail design. One is oil-soluble and water-dispersible, and the other is water-soluble. The phosphate esters are effective in preventing corrosion in both sweet and sour environments, and in high shear conditions. They form durable films on metal surfaces and help reduce naphthenic acid corrosion in refineries.
2.2.3 Corrosion Inhibitors in Pipelines
Pipelines are used to transport various fluids in power plants, including water, steam, and chemicals. The exposure to different substances and operating conditions can lead to corrosion and degradation of the pipeline materials. Corrosion inhibitors are employed in pipeline protection to ensure the integrity and longevity of the infrastructure.
- Cathodic Protection
Cathodic protection is an effective method to prevent corrosion in pipelines. It involves the use of sacrificial anodes or impressed current systems to create a cathodic environment, where the pipeline becomes the cathode and is protected from corrosion. This technique is particularly useful in alkaline media, where the pH promotes the formation of a passive film on the metal surface.
- Organic Corrosion Inhibitors
Organic corrosion inhibitors, such as azoles and soluble oils, are commonly used in pipeline systems. These inhibitors form a protective film on the metal surface, preventing the corrosive agents from reaching the metal. They are effective in neutral to alkaline environments and provide long-term corrosion protection.
2.3 Considerations for Corrosion Inhibitor Selection
When selecting corrosion inhibitors for power plant applications, several factors need to be considered. These include the specific operating conditions, the nature of the corrosive agents, compatibility with other treatment chemicals, environmental considerations, and cost-effectiveness. Our consultants at the Tasfyeh group can assist you in choosing the right corrosion inhibitor formulation that will provide optimal protection for your system.