Corrosion management in an age of resource depletion

Mineral depletion is an ongoing problem even though it is not commonly recognized. Depletion is not about “running out” of a resource; it is an ongoing process of increasing costs of extraction related to the progressive depletion of high-grade ores—a phenomenon only in part contrasted by technological progress. In this paper, we examine the relevance of depletion for the supply of the rare metals used for corrosion protection. We argue that several of these metals will soon be in short supply and that it is necessary to develop innovative approaches for producing industrial products resistant to corrosion and compatible with the new conditions of shortage. While recycling can be significantly helpful in maintaining the supply of rare metals, in the long run, substitution appears to be the best strategy. For instance, the gradual depletion of chromium to produce stainless steel may lead to a larger use of titanium as a structural material, owing to its natural corrosion resistance properties and to its abundance in Earth’s crust. The same holds for aluminum, an abundant material in Earth’s crust, which is characterized by a natural corrosion resistance. Other possible strategies involve moving to a wider use of biologically produced protective paints.