Alloying chromium with small amounts of platinum, palladium, iridium, rhodium, ruthenium, or osmium markedly improves its corrosion resistance to nonoxidizing acids such as sulfuric or hydrochloric acid. The presence of rhodium, palladium, or osmium has little influence on the resistance of chromium to an oxidizing acid such as nitric acid, while platinum, iridium, or ruthenium greatly increases corrosion rates in this medium. These phenomena can be explained in terms of the electrochemical and corrosion behavior of the metals involved and are related to the passive and transpassive behavior exhibited by chromium.