Corrosion testing is the best way to determine the ability of a given material to withstand corrosive forces. Testing is the only way sometimes to know for certain what the real-world behavior will turn out. Theoretical conclusions often lead to mixed results when a product or solution is used out there, without it having been thoroughly tested. Corrosion testing, therefore, involves the use of equipment to produce highly accelerated rates of corrosion. The process will be monitored, and important information gathered, to record performance, and to also help in the future development of the materials involved. It will also be a much faster way of knowing what will happen, as opposed to real-world testing that could take years.
There are tests that go beyond the usual salt-fog corrosion environment tests. Such tests are most suitable for materials that will be subjected to extreme environments like the acidic atmospheres in industrial areas, or the exhausts or fuel-burning devices where there is sulfur dioxide present.
There are several corrosion testing standards applied, depending on which industry is involved. You can read more here about those standards. The industries where corrosion testing is mostly applied are varied. The aerospace industry is one such example. The environment inside aircraft carriers is normally salty. The aircraft in there will, therefore, be constantly under such corrosive settings. Apart from that, there are frequent exhaust fumes from other aircraft as they take off and land. The aircraft also get to fly into areas with a salty atmosphere, such as cities near the ocean. There is, therefore, a need for corrosion testing for the material applied in the manufacture of such equipment and vehicles.
The automotive industry is also a beneficiary. There are few parts on automobiles that rarely get exposed to corrosion. The engine, the body, and all connective parts are under constant exposure or threat of corrosion. Rain, road salt, and stagnant water along the way, not to mention humidity in the environment are all examples of more threats.
The marine industry is another example. There is a common trait among most marine vessels where repairs are made harder by the corrosion of nuts and bolts. Such components must be heated to be removed. Other repairs are also affected, where hose clamps and other metallic or corrosive parts fail to give way or dislodge. Excessive corrosion is usually the culprit where most marine equipment fails to work. The constant exposure to saltwater makes it hard for such equipment and vessels not to undergo corrosion. All the materials and parts used in their manufacture, therefore, have to be extensively tested to meet the stringent standards.
The defense sector also needs such extensive testing. The personnel usually get deployed in some of the harshest environments, with their equipment playing a critical role in their survival and success. Imagine what corrosion would mean when such personnel is in enemy territory.
The medical world is also another example. Corrosion undermines sanitation standards. You will find medical staff relying on some strong and harsh solutions to disinfect their equipment and surfaces. Those are already bad for their health. A better approach would be to design medical products and equipment whose affinity for corrosion is minimal if any.