Corrosion Of Duplex Stainless Steel Research Articles

Application of double loop electrochemical potentiodynamic reactivation test to austenitic and duplex stainless steels

Double loop electrochemical potentiodynamic reactivation (DLEPR) tests are performed on an austenitic (317L) and an austeno-ferritic (UNS S31803) stainless steels. In order to optimise results, the standard electrochemical solution has been modified by adding NaCl to the composition and by increasing the concentration of H 2SO 4. Results show a high resistance to intergranular corrosion of the 317L heat treated at 675°C for 30 min to 24 h. On contrast, the duplex stainles steel corrosion resistance decreases with time of sensitisation. Low exposure time (1 h at 675°C) provides low reactivation current density whereas longer exposure time (10 h) shows an increase in the value of this reactivation current, whichis due to the formation of chromium carbides and sigma phase at grain boundaries leading to more chromium depleted areas. Heat treatment at 900°C shows a high reactivation proportional to σ-phase precipitation. The aim of this work is to validate the DLEPR technique for detecting susceptibility to intergranular corrosion of duplex stainless steels. This test is not yet normalised and could be used for on-site measurement.

Cavitation Corrosion of Duplex Stainless Steel in Seawater

Abstract A laboratory study was conducted on the cavitation corrosion behavior of a commercial cast duplex stainless steel (DSS) in seawater using an ultrasonically -induced cavitation facility. Ma...

Discussion of “Pitting Corrosion of Duplex Stainless Steels”

Abstract The following article discusses “Pitting Corrosion of Duplex Stainless Steels” by R. Sriram and D. Tromans, which was published in Corrosion 45, 10 (October 1989): p. 804.

Pitting Corrosion of Duplex Stainless Steels

Abstract The pitting corrosion of two duplex stainless steels was studied in chloride solutions. Phase compositions were determined by micro-analytical techniques and correlated with pitting behavi...

Crevice Corrosion of Duplex Stainless Steel in Simulated Sour Gas Environments

Abstract The crevice corrosion behavior of 22% Cr duplex stainless steel (SS), which has become widely used because of its high strength and stress corrosion cracking (SCC) resistance, was investigated in simulated sour gas conditions. The crevice corrosion is accelerated with increasing partial pressure of H2S and temperature, decreasing pH of the test solution, and the addition of sulfur. The duplex SS was more resistant to the crevice corrosion than AISI 316 SS in the H2S-Cl− environment. A simple model of the crevice corrosion, in which the initiation process and the mode of crevice corrosion were discussed, was proposed. The crevice corrosion incubation time based on this model was calculated, and the effect of the crevice gap and the partial pressure of H2S was clarified. The mode of the crevice corrosion changed with the partial pressure of H2S, which was explained by the stability of the NiS film and the depassivation pH in the crevice.