A good example of how crevice corrosion can be reproduced and accelerated in a laboratory environment is the formation of occluded cells with multiple crevice assemblies (MCAs), as described in the ASTM G78 Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Stainless Alloys in Seawater and Other Chloride-Containing Aqueous Environments.

Zebra mussels can be a real drag
Biofouling is ubiquitous in the marine environment. There are two main categories of fouling: 

• noncalcareous (soft)
• calcareous (hard)

Over 98% of pipelines are buried . No matter how well these pipelines are designed, constructed and protected, once in place they are subjected to environmental abuse, external damage, coating disbondments, inherent mill defects, soil movements/instability and third party damage.

Situations are sometimes met in service where aluminium bronze components are inadvertently exposed to electrical leakage currents either as a result of electrical faults resulting in current passing to earth, via a submerged pump for example, or as a result of incorrect positioning of impressed current cathodic protection equipment resulting in current passing from the water on to the metal equipment at one point and leaving it again at another. 

Silver Corrosion
Silver (Chemical symbol Ag) is a brilliant gray white metal that is quite soft and malleable. It is quite resistant to corrosion and does not oxidize easily, although it readily forms a surface tarnish of silver sulfide.

The main reason for the existence of the stainless steels is their resistance to corrosion. Chromium is the main alloying element, and the steel should contain at least 11 %. Chromium is a reactive element, but it and its alloys passivate and exhibit excellent resistance to many environments. A large number of stainless steels are available.

Nickel Corrosion
While nickel makes up 0.007 per cent of the earth's crust and is today one of our most useful metals, it was virtually unknown until the 1600s and was not isolated as an element until 1751. Early chemists called it Kupfer-Nickel (kupfer for copper), because nickel was originally found in association with copper ores, and nickel, after the German "Old Nick" or Satan, because it was initially so difficult to extract from those ores.

Iron and steel, the most commonly used metals, corrode in many media including most outdoor atmospheres. Usually they are selected not for their corrosion resistance but for such properties as strength, ease of fabrication, and cost. These differences show up in the rate of metal lost due to rusting.

Broadly speaking, bronzes are copper alloys in which the major alloying element is not zinc or nickel. Originally "bronze" described alloys with tin as the only or principal alloying element.

A tightly written valve specification that limits brass alloys to those containing no more than 15% zinc, or specification of proven dezincification-resistant yellow brass alloys. Further, manufacturers must be required to provide alloy designations or chemistry for the materials used in their valves and fittings.

These alloys contain zinc as the principal alloying element with or without other designated alloying elements such as iron, aluminum, nickel and silicon. The wrought alloys comprise three main families of brasses.

The type of backfill used in a groundbed depends on whether the cathodic protection system is sacrificial or impressed.

The corrosion resistance of a substrate can be improved by metallurgically bonding to the susceptible core alloy a surface layer of a metal or an alloy with good corrosion resistance.

The corrosion of metals can also occur in fresh water, seawater, salt solutions, and alkaline or basic media. In almost all of these environments, corrosion occurs importantly only if dissolved oxygen is also present. Water solutions rapidly dissolve oxygen from the air, and this is the source of the oxygen required in the corrosion process.