Crevice Corrosion Behavior of Nitrogen Bearing Austenitic Stainless Steels

摘要

The effect of nitrogen alloying on the initiation,propagation and repassivation of crevice corrosion of SUS 304and SUS 316 austenitic stainless steels was investigated throughpotentiostatic polarizations, cyclic polarizations and in-situmeasurements of depth profiles by the moiré method. The resultsshowed that nitrogen alloying in austenitic stainless steelsincreased to more noble values both the critical potential forsteady crevice corrosion, Vc, CREV, and the critical potential forrepassivation of crevice corrosion EC, CREV. Concerning the in-situmeasurements results, the dissolution rate just above therepassivation potential, VII*, decreased with nitrogen alloying forthe SUS 304 alloys, and did not change in the SUS 316 alloys. Theratio of repassivating picture elements increased in both SUS 304and SUS 316 with nitrogen alloying.