Abstract
Metastable pitting behavior for two grades of austenitic stainless steels, Type 304L (UNS S30403) and Type 316L (UNS S31603), has been investigated for a range of controlled hydrodynamic conditions: static, laminar, and turbulent (Reynolds numbers of 1,000, 2,000, 3,000, 10,000, 50,000, and 75,000). Metastable pitting was evident under all flow regimes. Stable pit growth was most evident for laminar flow conditions immediately before the transition to turbulent flow and during the approach to the so-called “critical velocity” (∼1.5 m/s) at Reynolds numbers of approximately 2,000 and 50,000, respectively. The corrosion behavior of the two austenitic stainless steels has been compared with a superduplex stainless steel, UNS S32760, exposed to the same hydrodynamic conditions.
