A COMPARISON OF THE CHROMIUM CONCENTRATION ON GRAIN-BOUNDARIES IN SENSITIZED STAINLESS-STEEL MEASURED BY ANALYTICAL ELECTRON-MICROSCOPY AND AN ELECTROCHEMICAL TECHNIQUE

A comparison is made between the average chromium concentration along the grain boundaries of sensitized (700°C/110 h) 308 stainless steel measured-by an electrochemical technique and the chromium concentrations measured by analytical electron microscopy (AEM) along a few, randomly selected grain boundaries. The bulk composition of the alloy included 20Cr-12Ni-0.06C, all expressed in wt%. The electrochemical technique indicated that nearly all of the grain boundaries had chromium concentrations between 12.0 and 14.0%. The boundaries measured by AEM had chromium concentrations of ∼13.0%. It is concluded that excellent agreement exists between the electrochemically determined values of chromium at the grain boundaries and those measured by AEM. © 1990.