Experimental Technique with a Pyramidal Indenter Demonstrating The Development of Pyramidal-Shaped Crevice Corrosion In Inconel 600

Abstract

-Inconel alloy 600 is widely used in applications requiring its excellent crevice corrosion resistance, e.g. with corrosive solutions. Cyclic polarization tests were carried out on Inconel work pieces immersed in a 5.5% NaCl solution at a temperature of 35±5 o C. One group of work pieces workpiece incorporated diamond pyramid hardness indentations while the other group of the workpieces did not. Hysteresis loops obtained from cyclic polarization test scans indicated passive film breakdown and non-passive film breakdown in work pieces with and without hardness test indentations, respectively. Microstructural observations indicated that all workpieces with the hardness test indentations developed crevice corrosion in the pyramidal indentations. Furthermore, microstructural observations revealed clearly developed dendritic structures in both indented and non-indented workpieces.