Corrosion and Protection research areas
- Aqueous and Localized Corrosion
- Atmospheric Degradation of Materials
- Cathodic Protection
- Corrosion and Protection of Steel in Concrete
- Conservation of Artifacts and Buildings
- Corrosion Inhibition
- Modelling
- Corrosion Monitoring and Testing
- Electronic Materials
- High-Temperature Degradation and Protection
- Light Metals
- Protective Coatings and Pretreatments
- Stress Corrosion Cracking and Corrosion Fatigue
Aqueous and localized corrosion
Investigators:
A major corrosion and protection centre must maintain active enquiry into basic corrosion mechanisms. It is quite surprising how many practical corrosion problems can be solved using fundamental knowledge generated in the last 10-15 years. In our case, much of this relates to stainless steels and to aluminium alloys, and led for example to improved understanding of the critical pitting temperature of stainless steel and the role of intermetallic particles in aluminium corrosion. The research embraces most aspects of aqueous and localized corrosion, including general corrosion, pitting, intergranular corrosion and filliform corrosion, and addresses the relationships between the corrosion processes and the condition of the alloy surface, extending to influences of thermochemical and surface treatments.
Atmospheric degradation of materials
Investigators:
Atmospheric corrosion and environmental degradation processes are ubiquitous and result in significant costs throughout the world. Tailored coatings are being studied for materials protection against environmental degradation of light metals, steels, cements, mortars and stones. The research focuses on the vulnerability of the coatings and especially the coating interface to corrosion-induced degradation and chemical damage. Further, models are being developed of atmospheric corrosion mechanisms of alloys, and influences on corrosion rates of environmental parameters, for instance salt deposition and pollutants.
Cathodic protection
Investigators:
Cathodic protection is a common and successful form of corrosion control in a variety of situations, for example, submerged marine structures, pipelines, chemical plant, oil storage and rebar corrosion in concrete. Current research is focusing on a number of areas including aluminium anodes, magnesium anodes, potential mapping, influences of defects on coated steel, monitoring of cathodic protection systems and protection of oilfield waters.
Corrosion and protection of steel in concrete
Investigators:
Prevention of corrosion of steel in reinforced concrete and repair of degraded material are of major importance in many parts of the world. One of the main corrosion problems with rebar steel in concrete is chloride ingress into the concrete causing pitting attack on the rebar. Research is investigating approaches to chloride removal, remedial measures and corrosion protection, including coatings. Cathodic protection of the rebar is a way of reversing this process and studies of the fundamental parameters associated with this emerging technology are an important activity.
Conservation of artifacts and buildings
Investigators:
The degradation of cultural heritage, as reflected in buildings, structures and artefacts, is a significant concern. Concerning degradation, the complex effects of interactions between pollutants and material surfaces need to be quantified to identify rate-determining processes and to provide predictive models. The previous also provides the scientific basis for the improvements of conservation procedures, with due consideration of the different initial condition of artefacts and of the practical and ethical constraints associated with the conservation procedures.
Corrosion inhibition
Investigators:
Inhibitors are chemicals that act to slow down corrosion. They are the preferred method of corrosion control in closed and recirculating cooling and heating systems using water as the heat transfer medium and are the only cost-effective method for corrosion control of steel pipelines in the oil and gas industry. Current research focuses on understanding the chemistry of corrosion and scale inhibition in order to develop new, more environmentally friendly, inhibitors, and practical aspects of the use of inhibitors, including efficiency and persistency of inhibition. The work involves a wide variety of electrochemical approaches, and high resolution surface analyses.
Modelling
Investigators:
Modelling of corrosion processes provides a test of our understanding, and leads to improved prediction of behaviour. Modelling work at the Centre has used a variety of techniques from ab initio analytical, numerical and Monte Carlo treatment of basic chemistry and electrochemistry of corrosion, through to the application of neural network methods to phenomenological modelling for prediction of behaviour.
Corrosion monitoring and testing
Investigators:
Several techniques of corrosion monitoring have been pioneered in the Centre and its associated companies. Innovation continues in the areas of electrochemical noise and impedance. Over the past 5 years there has also been intensive activity in stainless steel corrosion: for example, a "sigma probe" has been developed in collaboration with CAPCIS Ltd to detect deleterious phases in fabricated components.
Electronic materials
Investigators:
Electronics and photonics are integral to advances in most major industries, notably information technology. Oxidation and electrochemical processes play a key role in device manufacture through production of thin oxide films and control of material features from the nanoscale upwards. Materials of interest include metals, alloys and semiconductors. Recent work includes development of models of anodic oxidation of III-V semiconductors, in particular understanding migration behaviours of constituent anions and cations. Further, improvements in electrolytic capacitors are being sought from fundamental understanding of behaviours of low-level alloying additions in heat-treatments and surface treatments of aluminium foils, which have major influence on resultant capacitances.
High-temperature degradation and protection
Investigators:
Technological advances in some industrial processes (electric power generation, gasification, jet propulusion, steam reforming) are limited by the availability of high temperature materials. The material should be able to resist chemical degradation (oxidation, chloridation, sulphidation, carburization) and/or mechanical degradation (sliding wear, erosive wear), often under high creep or fatigue stresses. The consequences of component failure at high temperatures can be considerable, in respect of health and safety, the environment and profitability.
Research is underway to address some of the issues associated with materials performance at high temperatures, particularly on the role of high-temperature oxide scales in the protection of alloys and coatings, with emphasis on their mechanisms of growth, protective properties and breakdown in aggressive situations.
Light metals
Investigators:
Light metals play a vital role in everyday activities, with extensive applications in the aerospace, architecture, automotive, biomedical, electronic, packaging, lithographic sectors etc. In order to assist the exploitation of aluminium, magnesium, titanium and iron alloys, the structure/property/performance relationships are crucial, with probing from the nanoscale upwards assisted by the complimentary use of advanced electronoptical, electrochemical, surface analytical and structural approaches. From the previous, effective surface treatment and finishing for corrosion control are employed to ensure durability.
Protective coatings and pretreatments
Investigators:
Coatings are used either to slow or delay degradation processes, such as corrosion and wear, and/or to enhance a material's surface characteristics such as hardness or appearance. The most widely recognized coatings are organic, almost everything in daily use is painted, or metallic, such as galvanizing on steel. The aim of current coating research is to engineer high performance surfaces providing improved environmental sustainability of resources
Stress corrosion cracking and corrosion fatigue
Investigators:
Environmentally-assisted fracture of metals is one of the most alarming and expensive manifestations of aqueous corrosion. In recent years our scientific understanding of stress corrosion mechanisms has assisted the control of cracking problems in several industries. Recent work has focused on nickel-based alloys for power plant. A major facility for stress corrosion studies in high temperature, high pressure aqueous environments is being developed, with initial work addressing the difficult problems of predicting crack initiation and crack morphology in real components subject to residual stress.