Effect of Temperature to Crevice Corrosion of Austenitic and Duplex Stainless Steel in Deepwater

摘要

With continuous exploitation of oil and gas in deepwater, more and more stainless steels and Ni-based alloys has been used in subsea production system, such as manifold, well jumpers, umbilical and flange. Subsea installation is at high risk of crevice corrosion because of raw seawater ingress during tie-in operations and existence of crevice at the flange interface. Stainless steels are susceptible to crevice corrosion, and based on this corrosion risk, effect of temperature (4°C, 20°C and 60°C) on initiation and propagation of crevice corrosion of three kinds of stainless steels (AISI 316L, UNS S31803 and UNS S32750) is studied in this article. Crevice corrosion susceptibility of stainless steels is studied by cyclic voltammetry, and corrosion morphology is observed by SEM. Corrosion production is analyzed by EDS. The initiation and propagative orientation of crevice corrosion is analyzed at low temperature. The results show that UNS S32750 has a longest initial time of crevice corrosion, and it has highest crevice corrosion resistance.