Microstructural Evolution and Response to Double-Loop Reactivation Testing of Heat-Treated pH 13-8 Mo Martensitic Stainless Steel

摘要

The double loop electrochemical potentiokinetic reactivation (DL-EPR) test was used to investigate the intergranular and interlath corrosion susceptibility of pH 13-8 Mo as a function of heat treatment. Degree of sensitization was measured to the ratio of the peak current on a reverse (reactivation) scan to that on the forward anodic scan. Corrosion morphology was characterized by SEM, and microstructure by AEM. PH 13-8 Mo in the as-received condition was not sensitized. Precipitation-strengthening to the H925 temper caused susceptibility to intergranular corrosion, and averaging at H1150 caused susceptibility to interlath corrosion. Corrosion susceptibility was most likely caused by a classic Cr-depletion mechanism. 4 refs., 3 figs. (ERA citation 12:045737)