Cyclic Voltammetric Studies and Caustic Cracking of Steel at Various Temperatures

Abstract

Cyclic voltammetric studies were carried out for an iron electrode and for pressure vessel quality steel A516 in 1 and 7.73M sodium hydroxide solutions as a function of temperature. Cyclic voltammograms for strained electrodes of steel were also made. The stress corrosion cracking susceptibility was measured by the slow strain rate method. The examined temperature range was between 25° and 105°C. A correlation was found between the electrochemical behavior of unstrained electrodes (cyclovoltammograms) and the susceptibility to caustic cracking. A critical zone of temperatures, above which cyclic voltammograms are sensibly different and stress corrosion cracking occurs, was obtained.