Marine and offshore engineering

The vast majority of corrosion design issues faced in marine and offshore engineering involve water in one form or another. In that regard, the two principal media involved are seawater and formation waters (oilfield brines). Seawater, of course, surrounds offshore installations though may also be used as the medium in reservoir injection and other critical offshore process... 

Whilst careful design and informed forethought can often minimise or even prevent corrosion at little extra cost where the environmental conditions or the conditions of service are severe (as in most forms of marine and offshore engineering) reliable, secure and cost-effective corrosion control cannot be effectively achieved without considerable expense, although even in these circumstances good design can help to significantly reduce this. In... 

A wide variety of protective coating types and systems is available for corrosion control on external and internal surfaces of structural and process plant in marine and offshore engineering. These are discussed in detail elsewhere in this text, and the purpose here is to highlight the critical importance of certain design and related operational aspects which affect both the selection and performance of protective coating systems. The following design considerations should be made ... 

Low-carbon and chromium-nickel steels, certain copper, nickel and aluminium alloys (which are all widely used in marine and offshore engineering) are liable to exhibit stress-corrosion cracking whilst in service in specific environments, where combinations of perhaps relatively modest stress levels in material exposed to environments which are wet, damp or humid, and in the presence of certain gases or ions such as oxygen, chlorides, nitrates, hydroxides, chromates, nitrates, sulphides, sulphates, etc. 

This type of damage is dealt with comprehensively in Section 8.8. It can be particularly severe in seawater giving rise to cavitation corrosion or cavitation erosion mechanisms, and hence can be a considerable problem in marine and offshore engineering. Components that may suffer in this way include the suction faces of propellers, the suction areas of pump impellers and casings, diffusers, shaft brackets, rudders and diesel-engine cylinder liners. There is also evidence that cavitation conditions can develop in seawater, drilling mud and produced oil/gas waterlines with turbulent high rates of flow. 

Rowlands, J., Corrosion for Marine and Offshore Engineers, Marine Media (1986) Ashworth, V., Corrosion, Pergamon Press (1987)... 

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