Metals and their alloys are used in a multitude of changing conditions, and corrosion failures are not uncommon. The limited predictability of metal performance is the main reason why corrosion tests and corrosion monitoring programs are so important. Properly conducted, these tests can provide significant savings. In many cases, they are built-in requirements.
High-temperature corrosion is a form of corrosion that does not require the presence of a liquid electrolyte. In this corrosion mechanism, metals react directly with gaseous atoms in the atmosphere rather than ions in solution. Sometimes, this type of damage is called “dry corrosion” or “scaling.” The first quantitative analysis to oxidation behavior was made in the early 1920s with the postulation of the parabolic-rate theory of oxidation by Tammann and, independently, by Pilling and Bedworth.
The concentrations of various substances present in water in dissolved, colloidal, or suspended form are typically low but can vary considerably. The importance of these concentrations depends on the particular substance as well as the alloy, configuration, and function of the metallic structure with which the water comes into contact.