Corrosion is broadly defined as the degradation of a material or its properties, occurring because of a reaction with its environment. Whilst the term corrosion is most often used to describe the degradation of metals, it can also be used in relation to other materials such as plastics, ceramics and refractories.
Corrosion can take many forms depending upon the particular combination of conditions in which it occurs. In aqueous conditions, it can lead to general thinning of metals, causing a reduction in strength and collapse of structures, or can be highly localised leading to pitting and perforation of pipes or vessels. When a corrosive environment is combined with a source of stress, it can lead to the gradual formation of cracks through mechanisms such as stress corrosion cracking or corrosion fatigue.
We have encountered numerous cases where the corrosion has occurred due to the influence of microorganisms. This type of corrosion, referred to Microbially Influenced Corrosion (MIC), is frequently encountered in systems where water has been allowed to stagnate and/ or deposits have accumulated.
In high temperature environments, such as those found in power generation facilities or petrochemical plants, direct reaction of metals with hot gases can lead to thinning or cracks by mechanisms of high temperature oxidation or sulphidation.
Exposure to high temperatures can also cause the degradation of plastic and rubber (polymer) materials by altering their molecular structure. Degradation of polymers can also be caused by exposure to UV radiation in sunlight or to certain chemical environments.
Our experienced materials engineers and corrosion scientists have investigated numerous incidents involving corrosion failures in all types of materials. By conducting a thorough forensic investigation, they can identify particular corrosion mechanisms and the conditions that caused them.
Examples of corrosion incidents that they have investigated, both onshore and offshore include:
- Stress corrosion cracking in steam turbines, pipework, valves and vessels leading to escapes of fluids.
- Corrosion of tanks, wire ropes, holds, pipes and cranes leading to perforation or collapse.
- Microbially Influenced Corrosion leading to widespread pitting of ships’ tanks, and the perforation of pipework in poorly commissioned/maintained HVAC systems and petrochemical facilities.
- High temperature corrosion failures in boilers and gas turbines.
- Dezincification corrosion in brass plumbing fittings.
- Crevice corrosion of flanged joints and pipework.
- Degradation and environmental stress cracking of plastic vessels, pipework and fittings, exposed to incompatible chemicals.
- Corrosion and spoilage of cargos being carried by ships.
- High-temperature degradation of refractories and ceramics in furnaces.
If you would like further information, please contact us on 020 7726 4951 or complete our Contact Form.