Corrosion: Pros and cons

The aim of this work is to describe and analyze corrosion phenomena from unusual point of view and to show their usefulness, constructiveness, and attractiveness. The most common materials today in our life are metals. History is full of examples when corrosion does not only help in everyday life but saves humans lives. For instance, dissolved salts of iron are the best medicine against anemia. Without iron corrosion and some other metals, life would not exist. The cations Fe²⁺, the corrosion product of iron, are present in haemoglobin. Chlorophyll contains the corrosion product of magnesium (Mg²⁺). Vitamin B12 is a porphyrin containing corrosion product of cobalt (Co²⁺) in the center of large organic molecule. Corrosion of silver and as a result the presence of silver ions in water disinfects it. There are lakes containing clear and pure water because of the presence of silver ions in water that oxidize organic suspended matter and silver ions deposit with various anions on the bottoms of some lakes. We can mention “constructive” (desirable) corrosion in batteries, cathodic protection, cleaning of silverware, anodizing, bluing, and patina formation, to name a few. Another aspect of “beneficial” corrosion is a beauty of colors and forms of corrosion products of iron and other metals which attracts people of art in creating works of art. On the one hand, we can see the flip “constructive” side of corrosion and enjoy it. On the other hand, such unexpected approach to corrosion phenomena helps in teaching and education of the subject of corrosion and makes it attractive for new generations of students, engineers, and scientists.