SEDL / STP / STP1056-EB / STP25291S

The Importance of Ohmic Potential Drop in Crevice Corrosion

Shaw, BA
Materials Engineer, Martin Marietta Laboratories, Baltimore, MD

Pages: 9    Published: Jan 1990

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Abstract

The IR drop along the length of a crevice plays an important role in crevice corrosion. Two examples of how crevice corrosion can be induced by IR drop are presented and discussed. The first example involves crevice corrosion of a passive film forming metal whose polarization characteristics do not need to be altered to establish crevice corrosion. The second example involves the crevice corrosion of a passive film forming metal whose anodic polarization characteristics do need to be altered to establish crevice corrosion and the alteration results from chemistry changes within the crevice. Polarization behavior in environments representing those found inside and outside the crevice will be used to illustrate the role of IR drop in crevice corrosion.