Pitting is a form of localized corrosion that is often a concern in applications involving passivating metals and alloys in aggressive environments. This article describes the test methods for pitting corrosion. These methods include ASTM G 48, ASTM F 746, ASTM G 61, ASTM G 100, and electrochemical noise measurements. The visual examination, metallographic examination, and nondestructive inspection of pits are discussed. The article reviews the procedures for the use of standard charts, metal penetration, statistical analysis, and loss in mechanical properties to quantify the severity of pitting damage.

This article focuses on the different parameters that influence the pitting corrosion of passive metals. The parameters are environment, metal composition, potential, temperature, surface condition, alloy composition, stochastic nature of the processes, and inhibitors. In addition, the article provides a detailed discussion on the various stages of pitting. These include passive film breakdown, metastable pitting, pit growth, and pit stifling or death.